diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..c2065bc
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1,37 @@
+HELP.md
+.gradle
+build/
+!gradle/wrapper/gradle-wrapper.jar
+!**/src/main/**/build/
+!**/src/test/**/build/
+
+### STS ###
+.apt_generated
+.classpath
+.factorypath
+.project
+.settings
+.springBeans
+.sts4-cache
+bin/
+!**/src/main/**/bin/
+!**/src/test/**/bin/
+
+### IntelliJ IDEA ###
+.idea
+*.iws
+*.iml
+*.ipr
+out/
+!**/src/main/**/out/
+!**/src/test/**/out/
+
+### NetBeans ###
+/nbproject/private/
+/nbbuild/
+/dist/
+/nbdist/
+/.nb-gradle/
+
+### VS Code ###
+.vscode/
diff --git a/src/main/kotlin/config/BremerConfig.kt b/src/main/kotlin/config/BremerConfig.kt
index 5aab926..c420f26 100644
--- a/src/main/kotlin/config/BremerConfig.kt
+++ b/src/main/kotlin/config/BremerConfig.kt
@@ -4,7 +4,7 @@
 
 package net.piedpiper.bremer.config
 
-import net.piedpiper.bremer.service.app.LoginAppService
+import net.piedpiper.bremer.service.LoginService
 import org.apache.logging.log4j.LogManager
 import org.apache.logging.log4j.Logger
 import org.springframework.beans.factory.annotation.Qualifier
@@ -30,8 +30,8 @@
 @Configuration
 @EnableWebSecurity
 class WebSecurityConfig(
-    @Qualifier("bremer.service.LoginAppService")
-    private val loginAppService: LoginAppService
+    @Qualifier("bremer.service.LoginService")
+    private val loginService: LoginService
 ) {
     @Bean
     fun securityFilterChain(http: HttpSecurity): SecurityFilterChain {
@@ -57,7 +57,7 @@
                 .logoutSuccessUrl("/bremer/login.html?logout")
         }
             .csrf { it.disable() }
-            .userDetailsService(loginAppService)
+            .userDetailsService(loginService)
         return http.build()
     }
 }
diff --git a/src/main/kotlin/controller/api/AudioApiController.kt b/src/main/kotlin/controller/api/AudioApiController.kt
index c3ada9e..53cb909 100644
--- a/src/main/kotlin/controller/api/AudioApiController.kt
+++ b/src/main/kotlin/controller/api/AudioApiController.kt
@@ -5,7 +5,7 @@
 package net.piedpiper.bremer.controller.api
 
 import net.piedpiper.bremer.model.api.AudioListResponse
-import net.piedpiper.bremer.service.app.AudioAppService
+import net.piedpiper.bremer.service.AudioService
 import org.springframework.beans.factory.annotation.Qualifier
 import org.springframework.http.ResponseEntity
 import org.springframework.web.bind.annotation.GetMapping
@@ -13,21 +13,27 @@
 import org.springframework.web.bind.annotation.RequestParam
 import org.springframework.web.bind.annotation.RestController
 
-@RestController
+@RestController("bremer.controller.AudioApiController")
 @RequestMapping("bremer/api/audio")
 class AudioApiController(
-    @Qualifier("bremer.service.AudioAppService")
-    private val audioAppService: AudioAppService
+    @Qualifier("bremer.service.AudioService")
+    private val audioService: AudioService
 ) {
+    companion object {
+        private const val PAGE_LIMIT = 50
+    }
+
     @GetMapping
     fun getAudioList(
         @RequestParam("audio", required = false) audioName: String?,
         @RequestParam("artist", required = false) artistName: String?,
-        @RequestParam("album", required = false) albumName: String?
+        @RequestParam("album", required = false) albumName: String?,
+        @RequestParam("tag", required = false) tagName: String?
     ): ResponseEntity<AudioListResponse> =
-        ResponseEntity.ok(audioAppService.getByKeywords(audioName, artistName, albumName))
+        ResponseEntity.ok(audioService.getByKeywords(
+            audioName, artistName, albumName, tagName, PAGE_LIMIT))
 
     @GetMapping("history")
     fun getLeastRecentlyPlayedList(): ResponseEntity<AudioListResponse> =
-        ResponseEntity.ok(audioAppService.getLeastRecentlyAccessedAudio())
+        ResponseEntity.ok(audioService.getLeastRecentlyAccessedAudio(PAGE_LIMIT))
 }
\ No newline at end of file
diff --git a/src/main/kotlin/controller/api/PlaylistApiController.kt b/src/main/kotlin/controller/api/PlaylistApiController.kt
index 5e4b8ad..bc26301 100644
--- a/src/main/kotlin/controller/api/PlaylistApiController.kt
+++ b/src/main/kotlin/controller/api/PlaylistApiController.kt
@@ -5,11 +5,11 @@
 package net.piedpiper.bremer.controller.api
 
 import jakarta.validation.Valid
-import net.piedpiper.bremer.entity.AudioEntity
-import net.piedpiper.bremer.model.PlaylistAudioResponse
-import net.piedpiper.bremer.model.PlaylistListResponse
-import net.piedpiper.bremer.model.PlaylistRequest
-import net.piedpiper.bremer.service.app.PlaylistAppService
+import net.piedpiper.bremer.model.api.PlaylistAudioResponse
+import net.piedpiper.bremer.model.api.AllPlaylistResponse
+import net.piedpiper.bremer.model.api.PlaylistRequest
+import net.piedpiper.bremer.model.api.PlaylistAudioRequest
+import net.piedpiper.bremer.service.PlaylistService
 import org.springframework.beans.factory.annotation.Qualifier
 import org.springframework.http.ResponseEntity
 import org.springframework.web.bind.annotation.GetMapping
@@ -18,34 +18,45 @@
 import org.springframework.web.bind.annotation.PutMapping
 import org.springframework.web.bind.annotation.RequestBody
 import org.springframework.web.bind.annotation.RequestMapping
-import org.springframework.web.bind.annotation.RequestParam
 import org.springframework.web.bind.annotation.RestController
-import java.util.UUID
 
-@RestController
+@RestController("bremer.controller.PlaylistApiController")
 @RequestMapping("bremer/api/playlist")
 class PlaylistApiController(
-    @Qualifier("bremer.service.PlaylistAppService")
-    private val playlistAppService: PlaylistAppService,
+    @Qualifier("bremer.service.PlaylistService")
+    private val playlistService: PlaylistService,
 ) {
     @GetMapping
-    fun getAll(): ResponseEntity<PlaylistListResponse> =
-        ResponseEntity.ok(playlistAppService.getAllPlaylists())
-
-    @GetMapping("{slug}")
-    fun get(@PathVariable("slug") slug: String): ResponseEntity<PlaylistAudioResponse> =
-        ResponseEntity.ok(playlistAppService.getPlaylist(slug))
+    fun getAllPlaylists(): ResponseEntity<AllPlaylistResponse> =
+        ResponseEntity.ok(playlistService.getAllPlaylists())
 
     @PostMapping
-    fun create(
+    fun createPlaylist(
         @Valid @RequestBody request: PlaylistRequest
-    ): ResponseEntity<PlaylistAudioResponse> =
-        ResponseEntity.ok(playlistAppService.createPlaylist(request))
+    ): ResponseEntity<Void> {
+        playlistService.createPlaylist(request)
+        return ResponseEntity.ok(null)
+    }
 
     @PutMapping("{slug}")
-    fun update(
+    fun updatePlaylist(
         @PathVariable("slug") slug: String,
         @Valid @RequestBody request: PlaylistRequest
-    ): ResponseEntity<PlaylistAudioResponse> =
-        ResponseEntity.ok(playlistAppService.updatePlaylist(slug, request))
+    ): ResponseEntity<Void> {
+        playlistService.updatePlaylist(slug, request)
+        return ResponseEntity.ok(null)
+    }
+
+    @GetMapping("{slug}")
+    fun getAudioList(@PathVariable("slug") slug: String): ResponseEntity<PlaylistAudioResponse> =
+        ResponseEntity.ok(playlistService.getPlaylist(slug))
+
+    @PutMapping("audio/{slug}")
+    fun updateAudioList(
+        @PathVariable("slug") slug: String,
+        @Valid @RequestBody request: PlaylistAudioRequest
+    ): ResponseEntity<Void> {
+        playlistService.updatePlaylistAudioList(slug, request)
+        return ResponseEntity.ok(null)
+    }
 }
diff --git a/src/main/kotlin/controller/api/TagApiController.kt b/src/main/kotlin/controller/api/TagApiController.kt
new file mode 100644
index 0000000..406fd85
--- /dev/null
+++ b/src/main/kotlin/controller/api/TagApiController.kt
@@ -0,0 +1,62 @@
+/*
+ * Copyright (c) 2023. yo-saito. All Rights Reserved.
+ */
+
+package net.piedpiper.bremer.controller.api
+
+import jakarta.validation.Valid
+import net.piedpiper.bremer.model.api.TagAudioRequest
+import net.piedpiper.bremer.model.api.TagAudioResponse
+import net.piedpiper.bremer.model.api.TagRequest
+import net.piedpiper.bremer.model.api.AllTagsResponse
+import net.piedpiper.bremer.service.TagService
+import org.springframework.beans.factory.annotation.Qualifier
+import org.springframework.http.ResponseEntity
+import org.springframework.web.bind.annotation.*
+
+@RestController("bremer.controller.TagApiController")
+@RequestMapping("bremer/api/tag")
+class TagApiController(
+    @Qualifier("bremer.service.TagService")
+    private val tagService: TagService
+) {
+    @GetMapping
+    fun getAllTags(): ResponseEntity<AllTagsResponse> = ResponseEntity.ok(tagService.getAllTags())
+
+    @PostMapping
+    fun createTag(@Valid @RequestBody request: TagRequest): ResponseEntity<Void> {
+        tagService.createTag(request)
+        return ResponseEntity.ok(null)
+    }
+
+    @GetMapping("{slug}")
+    fun getAudioList(@PathVariable("slug") slug: String): ResponseEntity<TagAudioResponse> =
+        ResponseEntity.ok(tagService.getAudioListByTagSlug(slug))
+
+    @PostMapping("{slug}")
+    fun updateTag(
+        @PathVariable("slug") slug: String,
+        @Valid @RequestBody request: TagRequest
+    ): ResponseEntity<Void> {
+        tagService.updateTag(slug, request)
+        return ResponseEntity.ok(null)
+    }
+
+    @PutMapping("audio/{slug}")
+    fun addAudioList(
+        @PathVariable("slug") slug: String,
+        @Valid @RequestBody request: TagAudioRequest
+    ): ResponseEntity<Void> {
+        tagService.addTagToAudioList(slug, request)
+        return ResponseEntity.ok(null)
+    }
+
+    @DeleteMapping("audio/{slug}")
+    fun deleteAudioList(
+        @PathVariable("slug") slug: String,
+        @Valid @RequestBody request: TagAudioRequest
+    ): ResponseEntity<Void> {
+        tagService.deleteTagFromAudioList(slug, request)
+        return ResponseEntity.ok(null)
+    }
+}
\ No newline at end of file
diff --git a/src/main/kotlin/controller/view/AudioViewController.kt b/src/main/kotlin/controller/view/AudioViewController.kt
index 13a9a62..c1768de 100644
--- a/src/main/kotlin/controller/view/AudioViewController.kt
+++ b/src/main/kotlin/controller/view/AudioViewController.kt
@@ -5,7 +5,7 @@
 package net.piedpiper.bremer.controller.view
 
 import jakarta.servlet.http.HttpServletResponse
-import net.piedpiper.bremer.service.app.AudioAppService
+import net.piedpiper.bremer.service.AudioService
 import org.springframework.beans.factory.annotation.Qualifier
 import org.springframework.http.MediaType
 import org.springframework.stereotype.Controller
@@ -17,8 +17,8 @@
 @Controller("bremer.controller.AudioController")
 @RequestMapping("bremer/audio")
 class AudioViewController(
-    @Qualifier("bremer.service.AudioAppService")
-    private val audioAppService: AudioAppService
+    @Qualifier("bremer.service.AudioService")
+    private val audioService: AudioService
 ) {
 
     @GetMapping("{slug}")
@@ -26,7 +26,7 @@
         @PathVariable("slug") slug: String,
         response: HttpServletResponse
     ) {
-        val file = audioAppService.getAudioFile(slug)
+        val file = audioService.getAudioFile(slug)
         response.outputStream.use {
             response.setContentLengthLong(file.length())
             response.contentType = MediaType.APPLICATION_OCTET_STREAM_VALUE
diff --git a/src/main/kotlin/dao/AudioDao.kt b/src/main/kotlin/dao/AudioDao.kt
index a306032..cebd621 100644
--- a/src/main/kotlin/dao/AudioDao.kt
+++ b/src/main/kotlin/dao/AudioDao.kt
@@ -4,10 +4,7 @@
 
 package net.piedpiper.bremer.dao
 
-import net.piedpiper.bremer.entity.AlbumEntity
-import net.piedpiper.bremer.entity.ArtistEntity
-import net.piedpiper.bremer.entity.AudioEntity
-import net.piedpiper.bremer.entity.AudioNameEntity
+import net.piedpiper.bremer.entity.*
 import net.piedpiper.bremer.utils.SelectSQLBuilder
 import net.piedpiper.bremer.utils.WHERE_IN
 import org.apache.ibatis.annotations.*
@@ -30,6 +27,10 @@
     fun findAllByAlbumIdIn(@Param("albumIds") albumIds: List<Long>): List<AudioEntity>
 
     @ResultMap("net.piedpiper.bremer.AudioEntity")
+    @SelectProvider(type = Sql::class, method = "findAllByTagIdIn")
+    fun findAllByTagIdIn(@Param("tagIds") tagIds: List<Long>): List<AudioEntity>
+
+    @ResultMap("net.piedpiper.bremer.AudioEntity")
     @SelectProvider(type = Sql::class, method = "findAllByIdIn")
     fun findAllByIdIn(@Param("ids") ids: List<Long>): List<AudioEntity>
 
@@ -72,6 +73,7 @@
                     .leftOuterJoin(AudioNameEntity::class, "audio.id = audio_name.audio_id")
                     .toSql()
                     .WHERE_IN("audio.album_id", "albumIds", albumIds.size)
+                    .ORDER_BY("audio.album_id, audio.sequence")
                     .toString()
 
             @JvmStatic
@@ -82,6 +84,7 @@
                     .leftOuterJoin(AudioNameEntity::class, "audio.id = audio_name.audio_id")
                     .toSql()
                     .WHERE_IN("audio.id", "ids", ids.size)
+                    .ORDER_BY("audio.album_id, audio.sequence")
                     .toString()
 
             @JvmStatic
@@ -92,6 +95,19 @@
                     .leftOuterJoin(AudioNameEntity::class, "audio.id = audio_name.audio_id")
                     .toSql()
                     .WHERE_IN("audio.slug", "slugs", slugs.size)
+                    .ORDER_BY("audio.album_id, audio.sequence")
+                    .toString()
+
+            @JvmStatic
+            fun findAllByTagIdIn(@Param("tagIds") tagIds: List<Long>): String =
+                SelectSQLBuilder(AudioEntity::class)
+                    .leftOuterJoin(AlbumEntity::class, "audio.album_id = album.id")
+                    .leftOuterJoin(ArtistEntity::class, "album.artist_id = artist.id", AlbumEntity::class)
+                    .leftOuterJoin(AudioNameEntity::class, "audio.id = audio_name.audio_id")
+                    .leftOuterJoin(AudioTagEntity::class, "audio.id = audio_tag.audio_id")
+                    .toSql()
+                    .WHERE_IN("audio_tag.tag_id", "tagIds", tagIds.size)
+                    .ORDER_BY("audio.album_id, audio.sequence")
                     .toString()
 
             @JvmStatic
diff --git a/src/main/kotlin/dao/AudioTagDao.kt b/src/main/kotlin/dao/AudioTagDao.kt
new file mode 100644
index 0000000..c85688b
--- /dev/null
+++ b/src/main/kotlin/dao/AudioTagDao.kt
@@ -0,0 +1,40 @@
+/*
+ * Copyright (c) 2023. yo-saito. All Rights Reserved.
+ */
+
+package net.piedpiper.bremer.dao
+
+import net.piedpiper.bremer.entity.AudioTagEntity
+import net.piedpiper.bremer.utils.DaoUtils
+import org.apache.ibatis.annotations.*
+import org.springframework.stereotype.Repository
+
+@Repository("bremer.dao.AudioTagDao")
+@Mapper
+interface AudioTagDao {
+
+    @ResultMap("net.piedpiper.bremer.AudioTagEntity")
+    @Select("SELECT * FROM audio_tag WHERE audio_id = #{audioId} AND tag_id = #{tagId}")
+    fun findByAudioIdAndTagId(
+        @Param("audioId") audioId: Long,
+        @Param("tagId") tagId: Long
+    ): AudioTagEntity?
+
+    @UpdateProvider(type = Sql::class, method = "insertOne")
+    fun insertOne(@Param("entity") entity: AudioTagEntity): Boolean
+
+    @Delete("DELETE FROM audio_tag WHERE audio_id = #{audioId} AND tag_id = #{tagId}")
+    fun deleteOneByAudioIdAndTagId(
+        @Param("audioId") audioId: Long,
+        @Param("tagId") tagId: Long
+    ): Boolean
+
+    class Sql {
+        companion object {
+            @JvmStatic
+            @Options(useGeneratedKeys = true, keyColumn = "id")
+            fun insertOne(@Param("entity") entity: AudioTagEntity): String =
+                DaoUtils.insertOne(entity)
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/main/kotlin/dao/PlaylistDao.kt b/src/main/kotlin/dao/PlaylistDao.kt
index 5c024d1..83310b1 100644
--- a/src/main/kotlin/dao/PlaylistDao.kt
+++ b/src/main/kotlin/dao/PlaylistDao.kt
@@ -20,17 +20,24 @@
     fun findOneById(@Param("id") id: Long): PlaylistEntity?
 
     @ResultMap("net.piedpiper.bremer.PlaylistEntity")
+    @Select("SELECT * FROM playlist where slug = #{slug} FOR UPDATE")
+    fun findOneBySlugWithLock(@Param("slug") slug: String): PlaylistEntity?
+
+    @ResultMap("net.piedpiper.bremer.PlaylistEntity")
     @SelectProvider(type = Sql::class, method = "findOneBySlug")
     fun findOneBySlug(@Param("slug") slug: String): PlaylistEntity?
 
     @ResultMap("net.piedpiper.bremer.PlaylistEntity")
-    @Select("SELECT * FROM playlist")
-    fun findAll(): List<PlaylistEntity>
+    @Select("SELECT * FROM playlist ORDER BY sequence ASC")
+    fun findAllOrderBySequence(): List<PlaylistEntity>
 
     @InsertProvider(type = Sql::class, method = "insertOne")
     @Options(useGeneratedKeys = true, keyProperty = "id")
     fun insertOne(@Param("entity") entity: PlaylistEntity): Boolean
 
+    @Delete("DELETE FROM playlist WHERE slug = #{slug}")
+    fun deleteBySlug(@Param("slug") slug: String): Boolean
+
     @UpdateProvider(type = Sql::class, method = "updateOne")
     fun updateOne(@Param("entity") entity: PlaylistEntity)
 
diff --git a/src/main/kotlin/dao/TagDao.kt b/src/main/kotlin/dao/TagDao.kt
new file mode 100644
index 0000000..9d314b8
--- /dev/null
+++ b/src/main/kotlin/dao/TagDao.kt
@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2023. yo-saito. All Rights Reserved.
+ */
+
+package net.piedpiper.bremer.dao
+
+import net.piedpiper.bremer.entity.TagEntity
+import net.piedpiper.bremer.utils.DaoUtils
+import org.apache.ibatis.annotations.*
+import org.springframework.stereotype.Repository
+
+@Repository("bremer.dao.TagDao")
+@Mapper
+interface TagDao {
+
+    @ResultMap("net.piedpiper.bremer.TagEntity")
+    @Select("SELECT * FROM tag WHERE slug = #{slug}")
+    fun findOneBySlug(@Param("slug") slug: String): TagEntity?
+
+    @ResultMap("net.piedpiper.bremer.TagEntity")
+    @Select("SELECT * FROM tag WHERE slug = #{slug} FOR UPDATE")
+    fun findOneBySlugWithLock(@Param("slug") slug: String): TagEntity?
+
+    @ResultMap("net.piedpiper.bremer.TagEntity")
+    @Select("SELECT * FROM tag")
+    fun findAll(): List<TagEntity>
+
+    @ResultMap("net.piedpiper.bremer.TagEntity")
+    @Select("SELECT * FROM tag WHERE name LIKE CONCAT('%', #{nameLike}, '%') LIMIT #{limit}")
+    fun findAllByNameLikeLimit(
+        @Param("nameLike") nameLike: String,
+        @Param("limit") limit: Int
+    ): List<TagEntity>
+
+    @InsertProvider(type = Sql::class, method = "insertOne")
+    @Options(useGeneratedKeys = true, keyProperty = "id")
+    fun insertOne(@Param("entity") entity: TagEntity): Boolean
+
+    @UpdateProvider(type = Sql::class, method = "updateOne")
+    fun updateOne(@Param("entity") entity: TagEntity)
+
+    @Delete("DELETE FROM tag WHERE id = #{id}")
+    fun deleteById(@Param("id") id: Long): Boolean
+
+    class Sql {
+        companion object {
+            @JvmStatic
+            @Options(useGeneratedKeys = true, keyColumn = "id")
+            fun insertOne(@Param("entity") entity: TagEntity): String =
+                DaoUtils.insertOne(entity)
+
+            @JvmStatic
+            fun updateOne(@Param("entity") entity: TagEntity): String =
+                DaoUtils.updateOne(entity)
+        }
+    }
+}
\ No newline at end of file
diff --git a/src/main/kotlin/dao/UserDao.kt b/src/main/kotlin/dao/UserDao.kt
index 6c12a5c..3e2d8d7 100644
--- a/src/main/kotlin/dao/UserDao.kt
+++ b/src/main/kotlin/dao/UserDao.kt
@@ -17,5 +17,5 @@
 
     @ResultMap("net.piedpiper.bremer.UserEntity")
     @Select("SELECT * FROM user WHERE account_id = #{accountId}")
-    fun findByName(@Param("accountId") accountId: String): UserEntity?
+    fun findOneByName(@Param("accountId") accountId: String): UserEntity?
 }
\ No newline at end of file
diff --git a/src/main/kotlin/entity/Audio.kt b/src/main/kotlin/entity/Audio.kt
deleted file mode 100644
index f8f9f72..0000000
--- a/src/main/kotlin/entity/Audio.kt
+++ /dev/null
@@ -1,68 +0,0 @@
-/*
- * Copyright (c) 2023. yo-saito. All Rights Reserved.
- */
-
-package net.piedpiper.bremer.entity
-
-import net.piedpiper.bremer.utils.sql.Column
-import net.piedpiper.bremer.utils.sql.Table
-import java.time.LocalDateTime
-
-@Table("audio")
-data class AudioEntity(
-    @property:Column("id", insertable = false, updatable = false)
-    var id: Long = 0L,
-    @property:Column("slug")
-    var slug: String = "",
-    @property:Column("name")
-    var name: String = "",
-    @property:Column("album_id")
-    var albumId: Long = 0L,
-    @property:Column("sequence")
-    var sequence: Int = 0,
-    @property:Column("path")
-    var path: String = "",
-    // join
-    var album: AlbumEntity? = null,
-    var aliasNames: List<AudioNameEntity>? = null
-)
-
-@Table("audio_name")
-data class AudioNameEntity(
-    @property:Column("id", insertable = false, updatable = false)
-    var id: Long = 0L,
-    @property:Column("audio_id")
-    var audioId: Long = 0L,
-    @property:Column("name")
-    var name: String = ""
-)
-
-@Table("album")
-data class AlbumEntity(
-    @property:Column("id", insertable = false, updatable = false)
-    var id: Long = 0L,
-    @property:Column("artist_id")
-    var artistId: Long = 0L,
-    @property:Column("name")
-    var name: String = "",
-    // join
-    var artist: ArtistEntity? = null
-)
-
-@Table("artist")
-data class ArtistEntity(
-    @property:Column("id", insertable = false, updatable = false)
-    var id: Long = 0L,
-    @property:Column("name")
-    var name: String = "",
-)
-
-@Table("audio_play_history")
-data class AudioPlayHistoryEntity(
-    @property:Column("id", insertable = false, updatable = false)
-    var id: Long = 0L,
-    @property:Column("audio_id")
-    var audioId: Long = 0L,
-    @property:Column("last_played_at")
-    var lastPlayedAt: LocalDateTime = LocalDateTime.MIN
-)
diff --git a/src/main/kotlin/entity/Entity.kt b/src/main/kotlin/entity/Entity.kt
new file mode 100644
index 0000000..28836cf
--- /dev/null
+++ b/src/main/kotlin/entity/Entity.kt
@@ -0,0 +1,124 @@
+/*
+ * Copyright (c) 2023. yo-saito. All Rights Reserved.
+ */
+
+package net.piedpiper.bremer.entity
+
+import net.piedpiper.bremer.utils.sql.Column
+import net.piedpiper.bremer.utils.sql.Table
+import java.time.LocalDateTime
+
+@Table("audio")
+data class AudioEntity(
+    @property:Column("id", insertable = false, updatable = false)
+    var id: Long = 0L,
+    @property:Column("slug")
+    var slug: String = "",
+    @property:Column("name")
+    var name: String = "",
+    @property:Column("album_id")
+    var albumId: Long = 0L,
+    @property:Column("sequence")
+    var sequence: Int = 0,
+    @property:Column("path")
+    var path: String = "",
+    // join
+    var album: AlbumEntity? = null,
+    var aliasNames: List<AudioNameEntity>? = null
+)
+
+@Table("audio_name")
+data class AudioNameEntity(
+    @property:Column("id", insertable = false, updatable = false)
+    var id: Long = 0L,
+    @property:Column("audio_id")
+    var audioId: Long = 0L,
+    @property:Column("name")
+    var name: String = ""
+)
+
+@Table("album")
+data class AlbumEntity(
+    @property:Column("id", insertable = false, updatable = false)
+    var id: Long = 0L,
+    @property:Column("artist_id")
+    var artistId: Long = 0L,
+    @property:Column("name")
+    var name: String = "",
+    // join
+    var artist: ArtistEntity? = null
+)
+
+@Table("artist")
+data class ArtistEntity(
+    @property:Column("id", insertable = false, updatable = false)
+    var id: Long = 0L,
+    @property:Column("name")
+    var name: String = "",
+)
+
+@Table("audio_tag")
+data class AudioTagEntity(
+    @property:Column("id", insertable = false, updatable = false)
+    var id: Long = 0L,
+    @property:Column("audio_id")
+    var audioId: Long = 0L,
+    @property:Column("tag_id")
+    var tagId: Long = 0L
+)
+
+@Table("user")
+data class UserEntity(
+    @property:Column("id", insertable = false, updatable = false)
+    var id: Long = 0L,
+    @property:Column("account_id")
+    var accountId: String = "",
+    @property:Column("secret")
+    var secret: String = "",
+)
+
+@Table("audio_play_history")
+data class AudioPlayHistoryEntity(
+    @property:Column("id", insertable = false, updatable = false)
+    var id: Long = 0L,
+    @property:Column("audio_id")
+    var audioId: Long = 0L,
+    @property:Column("last_played_at")
+    var lastPlayedAt: LocalDateTime = LocalDateTime.MIN
+)
+
+@Table("playlist")
+data class PlaylistEntity(
+    @property:Column("id", insertable = false, updatable = false)
+    var id: Long = 0L,
+    @property:Column("slug")
+    var slug: String = "",
+    @property:Column("name")
+    var name: String = "",
+    @property:Column("sequence")
+    var sequence: Int = 0,
+    // join
+    var playlistAudio: List<PlaylistAudioEntity> = mutableListOf()
+)
+
+@Table("playlist_audio")
+data class PlaylistAudioEntity(
+    @property:Column("id", insertable = false, updatable = false)
+    var id: Long = 0L,
+    @property:Column("playlist_id")
+    var playlistId: Long = 0L,
+    @property:Column("sequence")
+    var sequence: Int = 0,
+    @property:Column("audio_id")
+    var audioId: Long = 0L
+)
+
+@Table("tag")
+data class TagEntity(
+    @property:Column("id", insertable = false, updatable = false)
+    var id: Long = 0L,
+    @property:Column("slug")
+    var slug: String = "",
+    @property:Column("name")
+    var name: String = "",
+)
diff --git a/src/main/kotlin/entity/Playlist.kt b/src/main/kotlin/entity/Playlist.kt
deleted file mode 100644
index e9680a2..0000000
--- a/src/main/kotlin/entity/Playlist.kt
+++ /dev/null
@@ -1,33 +0,0 @@
-/*
- * Copyright (c) 2023. yo-saito. All Rights Reserved.
- */
-
-package net.piedpiper.bremer.entity
-
-import net.piedpiper.bremer.utils.sql.Column
-import net.piedpiper.bremer.utils.sql.Table
-
-
-@Table("playlist")
-data class PlaylistEntity(
-    @property:Column("id", insertable = false, updatable = false)
-    var id: Long = 0L,
-    @property:Column("slug")
-    var slug: String = "",
-    @property:Column("name")
-    var name: String = "",
-    // join
-    var playlistAudio: List<PlaylistAudioEntity> = mutableListOf()
-)
-
-@Table("playlist_audio")
-data class PlaylistAudioEntity(
-    @property:Column("id", insertable = false, updatable = false)
-    var id: Long = 0L,
-    @property:Column("playlist_id")
-    var playlistId: Long = 0L,
-    @property:Column("sequence")
-    var sequence: Int = 0,
-    @property:Column("audio_id")
-    var audioId: Long = 0L
-)
diff --git a/src/main/kotlin/entity/User.kt b/src/main/kotlin/entity/User.kt
deleted file mode 100644
index 90f2d5c..0000000
--- a/src/main/kotlin/entity/User.kt
+++ /dev/null
@@ -1,18 +0,0 @@
-/*
- * Copyright (c) 2023. yo-saito. All Rights Reserved.
- */
-
-package net.piedpiper.bremer.entity
-
-import net.piedpiper.bremer.utils.sql.Column
-import net.piedpiper.bremer.utils.sql.Table
-
-@Table("user")
-data class UserEntity(
-    @property:Column("id", insertable = false, updatable = false)
-    var id: Long = 0L,
-    @property:Column("account_id")
-    var accountId: String = "",
-    @property:Column("secret")
-    var secret: String = "",
-)
\ No newline at end of file
diff --git a/src/main/kotlin/model/BremerUser.kt b/src/main/kotlin/model/BremerUser.kt
new file mode 100644
index 0000000..bb1da09
--- /dev/null
+++ b/src/main/kotlin/model/BremerUser.kt
@@ -0,0 +1,21 @@
+/*
+ * Copyright (c) 2023. yo-saito. All Rights Reserved.
+ */
+
+package net.piedpiper.bremer.model
+
+import net.piedpiper.bremer.entity.UserEntity
+import org.springframework.security.core.GrantedAuthority
+import org.springframework.security.core.userdetails.UserDetails
+
+class BremerUser(
+    private val user: UserEntity
+) : UserDetails {
+    override fun getAuthorities(): MutableCollection<out GrantedAuthority> = mutableListOf()
+    override fun getUsername(): String = user.accountId
+    override fun getPassword(): String = user.secret
+    override fun isAccountNonExpired(): Boolean = true
+    override fun isAccountNonLocked(): Boolean = true
+    override fun isCredentialsNonExpired(): Boolean = true
+    override fun isEnabled(): Boolean = true
+}
diff --git a/src/main/kotlin/model/api/Audio.kt b/src/main/kotlin/model/api/Audio.kt
deleted file mode 100644
index 61171c8..0000000
--- a/src/main/kotlin/model/api/Audio.kt
+++ /dev/null
@@ -1,25 +0,0 @@
-/*
- * Copyright (c) 2023. yo-saito. All Rights Reserved.
- */
-
-package net.piedpiper.bremer.model.api
-
-import net.piedpiper.bremer.entity.AudioEntity
-
-data class AudioListResponse(
-    private val entities: List<AudioEntity>
-) {
-    val audio: List<Audio> =
-        entities.map { Audio(it) }
-
-    data class Audio(
-        private val entity: AudioEntity
-    ) {
-        val name: String = entity.name
-        val slug: String = entity.slug
-        val artist: String? = entity?.album?.artist?.name
-        val album: String? = entity?.album?.name
-        var sequence: Int? = if (entity?.sequence == 0) { entity?.sequence } else { null }
-        var aliasNames: List<String>? = entity?.aliasNames?.map { it.name }
-    }
-}
\ No newline at end of file
diff --git a/src/main/kotlin/model/api/Playlist.kt b/src/main/kotlin/model/api/Playlist.kt
deleted file mode 100644
index 1e3b06a..0000000
--- a/src/main/kotlin/model/api/Playlist.kt
+++ /dev/null
@@ -1,50 +0,0 @@
-/*
- * Copyright (c) 2023. yo-saito. All Rights Reserved.
- */
-
-package net.piedpiper.bremer.model
-
-import com.fasterxml.jackson.annotation.JsonInclude
-import com.fasterxml.jackson.annotation.JsonProperty
-import jakarta.validation.constraints.NotBlank
-import net.piedpiper.bremer.entity.AudioEntity
-import net.piedpiper.bremer.entity.PlaylistEntity
-
-
-data class PlaylistListResponse(
-    private val entities: List<PlaylistEntity>
-) {
-    val playlist: List<Playlist> = entities.map { Playlist(it.name, it.slug) }
-
-    data class Playlist(
-        val name: String,
-        val slug: String
-    )
-}
-
-data class PlaylistRequest(
-    @field:NotBlank
-    val name: String = "",
-
-    @field:JsonProperty("audio_slugs")
-    val audioSlugs: List<String> = mutableListOf()
-)
-
-class PlaylistAudioResponse(
-    private val playlistEntity: PlaylistEntity,
-    private val audioEntityList: List<AudioEntity>
-) {
-    val name: String = playlistEntity.name
-    val slug: String = playlistEntity.slug
-
-    @field:JsonProperty("audio_list")
-    val audioList: List<Audio> = audioEntityList.map { Audio(it) }
-
-    @JsonInclude(JsonInclude.Include.NON_NULL)
-    class Audio(private val entity: AudioEntity) {
-        val name: String = entity.name
-        val slug: String = entity.slug
-        val artist: String? = entity.album?.artist?.name
-        val album: String? = entity.album?.name
-    }
-}
diff --git a/src/main/kotlin/model/api/Request.kt b/src/main/kotlin/model/api/Request.kt
new file mode 100644
index 0000000..13292be
--- /dev/null
+++ b/src/main/kotlin/model/api/Request.kt
@@ -0,0 +1,28 @@
+/*
+ * Copyright (c) 2023. yo-saito. All Rights Reserved.
+ */
+
+package net.piedpiper.bremer.model.api
+
+import com.fasterxml.jackson.annotation.JsonProperty
+import jakarta.validation.constraints.NotBlank
+
+data class PlaylistRequest(
+    @field:NotBlank
+    val name: String = "",
+)
+
+data class PlaylistAudioRequest(
+    @field:JsonProperty("audio_slugs")
+    val audioSlugs: List<String> = emptyList()
+)
+
+data class TagRequest(
+    @field:NotBlank
+    val name: String = ""
+)
+
+data class TagAudioRequest(
+    @field:JsonProperty("audio_slugs")
+    val audioSlugs: List<String> = emptyList()
+)
diff --git a/src/main/kotlin/model/api/Response.kt b/src/main/kotlin/model/api/Response.kt
new file mode 100644
index 0000000..590cdd6
--- /dev/null
+++ b/src/main/kotlin/model/api/Response.kt
@@ -0,0 +1,81 @@
+/*
+ * Copyright (c) 2023. yo-saito. All Rights Reserved.
+ */
+
+package net.piedpiper.bremer.model.api
+
+import com.fasterxml.jackson.annotation.JsonProperty
+import net.piedpiper.bremer.entity.AudioEntity
+import net.piedpiper.bremer.entity.PlaylistEntity
+import net.piedpiper.bremer.entity.TagEntity
+
+data class Audio(
+    private val audioEntity: AudioEntity
+) {
+    val name: String = audioEntity.name
+    val slug: String = audioEntity.slug
+    val artist: String? = audioEntity?.album?.artist?.name
+    val album: String? = audioEntity?.album?.name
+    var sequence: Int? = if (audioEntity?.sequence == 0) {
+        audioEntity?.sequence
+    } else {
+        null
+    }
+    var aliasNames: List<String>? = audioEntity?.aliasNames?.map { it.name }
+}
+
+data class Tag(
+    private val tagEntity: TagEntity
+) {
+    val slug: String = tagEntity.slug
+    val name: String = tagEntity.name
+}
+
+data class AllPlaylistResponse(
+    private val entities: List<PlaylistEntity>
+) {
+    val playlist: List<Playlist> = entities.map { Playlist(it.name, it.sequence, it.slug) }
+
+    data class Playlist(
+        val name: String,
+        var sequence: Int,
+        val slug: String
+    )
+}
+
+data class AudioListResponse(
+    private val entities: List<AudioEntity> = emptyList()
+) {
+    @field:JsonProperty("audio_list")
+    val audioList: List<Audio> =
+        entities.map { Audio(it) }
+}
+
+data class PlaylistAudioResponse(
+    private val playlistEntity: PlaylistEntity,
+    private val audioEntityList: List<AudioEntity>? = null
+) {
+    val name: String = playlistEntity.name
+    val slug: String = playlistEntity.slug
+
+    @field:JsonProperty("audio_list")
+    val audioList: List<Audio>? = audioEntityList?.map { Audio(it) } ?: null
+}
+
+data class TagAudioResponse(
+    private val tagEntity: TagEntity,
+    private val audioEntityList: List<AudioEntity>
+) {
+    val name: String = tagEntity.name
+    val slug: String = tagEntity.slug
+
+    @field:JsonProperty("audio_list")
+    val audioList: List<Audio> = audioEntityList.map { Audio(it) }
+}
+
+
+data class AllTagsResponse(
+    private val tagEntities: List<TagEntity>
+) {
+    val tags: List<Tag> = tagEntities.map { Tag(it) }
+}
diff --git a/src/main/kotlin/model/api/User.kt b/src/main/kotlin/model/api/User.kt
deleted file mode 100644
index a369045..0000000
--- a/src/main/kotlin/model/api/User.kt
+++ /dev/null
@@ -1,21 +0,0 @@
-/*
- * Copyright (c) 2023. yo-saito. All Rights Reserved.
- */
-
-package net.piedpiper.bremer.model.api
-
-import net.piedpiper.bremer.entity.UserEntity
-import org.springframework.security.core.GrantedAuthority
-import org.springframework.security.core.userdetails.UserDetails
-
-class BremerUser(
-    private val user: UserEntity
-) : UserDetails {
-    override fun getAuthorities(): MutableCollection<out GrantedAuthority> = mutableListOf()
-    override fun getUsername(): String = user.accountId
-    override fun getPassword(): String = user.secret
-    override fun isAccountNonExpired(): Boolean = true
-    override fun isAccountNonLocked(): Boolean = true
-    override fun isCredentialsNonExpired(): Boolean = true
-    override fun isEnabled(): Boolean = true
-}
diff --git a/src/main/kotlin/repository/AudioRepository.kt b/src/main/kotlin/repository/AudioRepository.kt
deleted file mode 100644
index 8e0ca5f..0000000
--- a/src/main/kotlin/repository/AudioRepository.kt
+++ /dev/null
@@ -1,70 +0,0 @@
-/*
- * Copyright (c) 2023. yo-saito. All Rights Reserved.
- */
-
-package net.piedpiper.bremer.repository
-
-import net.piedpiper.bremer.dao.AlbumDao
-import net.piedpiper.bremer.dao.ArtistDao
-import net.piedpiper.bremer.dao.AudioDao
-import net.piedpiper.bremer.dao.AudioPlayHistoryDao
-import net.piedpiper.bremer.entity.AudioEntity
-import net.piedpiper.bremer.entity.AudioPlayHistoryEntity
-import org.springframework.beans.factory.annotation.Qualifier
-import org.springframework.stereotype.Repository
-import java.time.LocalDateTime
-
-@Repository("bremer.repository.AudioRepository")
-class AudioRepository(
-    @Qualifier("bremer.dao.AudioDao")
-    private val audioDao: AudioDao,
-    @Qualifier("bremer.dao.ArtistDao")
-    private val artistDao: ArtistDao,
-    @Qualifier("bremer.dao.AlbumDao")
-    private val albumDao: AlbumDao,
-    @Qualifier("bremer.dao.AudioPlayHistoryDao")
-    private val audioPlayHistoryDao: AudioPlayHistoryDao
-) {
-
-    fun findOneBySlug(slug: String): AudioEntity? = audioDao.findOneBySlug(slug)
-
-    fun findAllByIdIn(ids: List<Long>): List<AudioEntity> =
-        if (ids.isNotEmpty()) audioDao.findAllByIdIn(ids) else emptyList()
-
-    fun findAllBySlugIn(slugs: List<String>): List<AudioEntity> =
-        if (slugs.isNotEmpty()) audioDao.findAllBySlugIn(slugs) else emptyList()
-
-    fun findAllByNameLikeLimit(nameLike: String, limit: Int): List<AudioEntity> =
-        audioDao.findAllByNameLikeLimit(nameLike, limit)
-
-    fun findAllByArtistNameLikeLimit(artistNameLike: String, limit: Int): List<AudioEntity> {
-        val artists = artistDao.findAllByNameLikeLimit(artistNameLike, limit)
-        if (artists.isEmpty()) {
-            return emptyList()
-        }
-        val albums = albumDao.findAllByArtistIdInLimit(artists.map { it.id }.distinct(), limit)
-        if (albums.isEmpty()) {
-            return emptyList()
-        }
-        return audioDao.findAllByAlbumIdIn(albums.map { it.id }.distinct())
-    }
-
-    fun findAllByAlbumNameLikeLimit(albumNameLike: String, limit: Int): List<AudioEntity> {
-        val albums = albumDao.findAllByNameLikeLimit(albumNameLike, limit)
-        return if (albums.isNotEmpty()) audioDao
-            .findAllByAlbumIdIn(albums.map { it.id }) else emptyList()
-    }
-
-    fun findAllLruLimit(limit: Int): List<AudioEntity> {
-        val historyMap = audioPlayHistoryDao.findAllOrderLastPlayedAtDescLimit(limit)
-            .associateBy { it.audioId }
-        return if (historyMap.isNotEmpty()) audioDao
-            .findAllByIdIn(historyMap.keys.map { it })
-            .sortedByDescending {
-                historyMap[it.id]?.lastPlayedAt ?: LocalDateTime.MIN
-            } else emptyList()
-    }
-
-    fun saveAudioPlayHistory(entity: AudioPlayHistoryEntity) =
-        audioPlayHistoryDao.insertOrUpdateOne(entity)
-}
\ No newline at end of file
diff --git a/src/main/kotlin/repository/PlaylistRepository.kt b/src/main/kotlin/repository/PlaylistRepository.kt
deleted file mode 100644
index cb85ea2..0000000
--- a/src/main/kotlin/repository/PlaylistRepository.kt
+++ /dev/null
@@ -1,63 +0,0 @@
-/*
- * Copyright (c) 2023. yo-saito. All Rights Reserved.
- */
-
-package net.piedpiper.bremer.repository
-
-import net.piedpiper.bremer.dao.PlaylistAudioDao
-import net.piedpiper.bremer.dao.PlaylistDao
-import net.piedpiper.bremer.entity.PlaylistEntity
-import org.springframework.beans.factory.annotation.Qualifier
-import org.springframework.stereotype.Repository
-import org.springframework.transaction.annotation.Transactional
-
-@Repository("bremer.repository.PlaylistRepository")
-class PlaylistRepository(
-    @Qualifier("bremer.dao.PlaylistDao")
-    private val playlistDao: PlaylistDao,
-    @Qualifier("bremer.dao.PlaylistAudioDao")
-    private val playlistAudioDao: PlaylistAudioDao
-) {
-
-    fun findOneById(id: Long): PlaylistEntity? = playlistDao.findOneById(id)
-
-    fun findBySlug(slug: String): PlaylistEntity? = playlistDao.findOneBySlug(slug)
-
-    fun findAll(): List<PlaylistEntity> = playlistDao.findAll()
-
-    fun insertOne(playlist: PlaylistEntity): Long {
-        playlistDao.insertOne(playlist)
-        playlist.playlistAudio?.forEach {
-            it.playlistId = playlist.id
-            playlistAudioDao.insertOne(it)
-        }
-        return playlist.id
-    }
-
-    fun updateOne(playlist: PlaylistEntity) {
-        // playlist
-        playlistDao.updateOne(playlist)
-        // playlist_audio
-        val oldAudio = playlistDao.findOneById(playlist.id)
-            ?.playlistAudio
-            ?.associate { it.id to it }
-            ?.toMutableMap()
-            ?: mutableMapOf()
-        val oldSize = oldAudio?.size ?: 0
-        playlist?.playlistAudio?.forEachIndexed { idx, entity ->
-            if (idx >= oldSize) {
-                playlistAudioDao.insertOne(entity)
-            } else {
-                playlistAudioDao.updateOne(entity)
-                oldAudio.remove(entity.id)
-            }
-        }
-        deleteAllByIds(oldAudio.keys.toList())
-    }
-
-    fun deleteAllByIds(ids: List<Long>) {
-        if (ids.isNotEmpty()) {
-            playlistAudioDao.deleteAllByIds(ids)
-        }
-    }
-}
\ No newline at end of file
diff --git a/src/main/kotlin/repository/UserRepository.kt b/src/main/kotlin/repository/UserRepository.kt
deleted file mode 100644
index b010959..0000000
--- a/src/main/kotlin/repository/UserRepository.kt
+++ /dev/null
@@ -1,18 +0,0 @@
-/*
- * Copyright (c) 2023. yo-saito. All Rights Reserved.
- */
-
-package net.piedpiper.bremer.repository
-
-import net.piedpiper.bremer.dao.UserDao
-import net.piedpiper.bremer.entity.UserEntity
-import org.springframework.beans.factory.annotation.Qualifier
-import org.springframework.stereotype.Repository
-
-@Repository("bremer.dao.UserRepository")
-class UserRepository(
-    @Qualifier("bremer.dao.UserDao")
-    private val userDao: UserDao
-) {
-    fun findByName(name: String): UserEntity? = userDao.findByName(name)
-}
\ No newline at end of file
diff --git a/src/main/kotlin/service/AudioService.kt b/src/main/kotlin/service/AudioService.kt
new file mode 100644
index 0000000..9805805
--- /dev/null
+++ b/src/main/kotlin/service/AudioService.kt
@@ -0,0 +1,120 @@
+/*
+ * Copyright (c) 2023. yo-saito. All Rights Reserved.
+ */
+
+package net.piedpiper.bremer.service
+
+import net.piedpiper.bremer.dao.*
+import net.piedpiper.bremer.entity.AudioEntity
+import net.piedpiper.bremer.entity.AudioPlayHistoryEntity
+import net.piedpiper.bremer.exception.NotFoundException
+import net.piedpiper.bremer.model.api.AudioListResponse
+import org.springframework.beans.factory.annotation.Qualifier
+import org.springframework.stereotype.Service
+import org.springframework.transaction.annotation.Transactional
+import java.io.File
+import java.time.LocalDateTime
+import java.time.ZoneId
+
+@Service("bremer.service.AudioService")
+class AudioService(
+    @Qualifier("bremer.dao.AudioDao")
+    private val audioDao: AudioDao,
+    @Qualifier("bremer.dao.ArtistDao")
+    private val artistDao: ArtistDao,
+    @Qualifier("bremer.dao.AlbumDao")
+    private val albumDao: AlbumDao,
+    @Qualifier("bremer.dao.AudioPlayHistoryDao")
+    private val audioPlayHistoryDao: AudioPlayHistoryDao,
+    @Qualifier("bremer.dao.TagDao")
+    private val tagDao: TagDao
+) {
+
+    /** 音楽ファイル取得 */
+    @Transactional
+    fun getAudioFile(slug: String): File {
+        val audio = audioDao.findOneBySlug(slug) ?: throw NotFoundException()
+        val file = File(audio.path)
+        if (!file.exists()) {
+            throw NotFoundException()
+        }
+        audioPlayHistoryDao.insertOrUpdateOne(
+            AudioPlayHistoryEntity(
+                audioId = audio.id,
+                lastPlayedAt = LocalDateTime.now(ZoneId.of("Asia/Tokyo"))
+            )
+        )
+        return file
+    }
+
+    /** キーワード検索 */
+    @Transactional
+    fun getByKeywords(
+        audioNameLike: String?,
+        artistNameLike: String?,
+        albumNameLike: String?,
+        tagNameLike: String?,
+        pageSize: Int
+    ): AudioListResponse {
+        val set = mutableSetOf<AudioEntity>()
+        if (audioNameLike?.isNotEmpty() == true) {
+            set.addAll(audioDao.findAllByNameLikeLimit(audioNameLike, pageSize))
+        }
+        if (artistNameLike?.isNotEmpty() == true && set.size <= pageSize) {
+            set.addAll(findAllByArtistNameLikeLimit(artistNameLike, pageSize))
+        }
+        if (albumNameLike?.isNotEmpty() == true && set.size <= pageSize) {
+            set.addAll(findAllByAlbumNameLikeLimit(albumNameLike, pageSize))
+        }
+        if (tagNameLike?.isNotEmpty() == true && set.size <= pageSize) {
+            set.addAll(findAllByTagNameLikeLimit(tagNameLike, pageSize))
+        }
+        return AudioListResponse(
+            set.sortedWith(compareBy({ it.albumId }, { it.sequence }))
+                .take(pageSize)
+                .toList()
+        )
+    }
+
+    /** 最近再生した曲一覧を取得 */
+    @Transactional
+    fun getLeastRecentlyAccessedAudio(pageSize: Int): AudioListResponse {
+        val historyMap = audioPlayHistoryDao.findAllOrderLastPlayedAtDescLimit(pageSize)
+            .associateBy { it.audioId }
+        return if (historyMap.isNotEmpty())
+            audioDao.findAllByIdIn(historyMap.keys.map { it })
+                .sortedByDescending {
+                    historyMap[it.id]?.lastPlayedAt ?: LocalDateTime.MIN
+                }.let {
+                    AudioListResponse(it)
+                }
+        else AudioListResponse()
+    }
+
+    private fun findAllByArtistNameLikeLimit(
+        artistNameLike: String,
+        limit: Int
+    ): List<AudioEntity> {
+        val artists = artistDao.findAllByNameLikeLimit(artistNameLike, limit)
+        if (artists.isEmpty()) {
+            return emptyList()
+        }
+        val albums = albumDao.findAllByArtistIdInLimit(artists.map { it.id }.distinct(), limit)
+        if (albums.isEmpty()) {
+            return emptyList()
+        }
+        return audioDao.findAllByAlbumIdIn(albums.map { it.id }.distinct())
+    }
+
+    private fun findAllByAlbumNameLikeLimit(albumNameLike: String, limit: Int): List<AudioEntity> {
+        val albums = albumDao.findAllByNameLikeLimit(albumNameLike, limit)
+        return if (albums.isNotEmpty()) audioDao
+            .findAllByAlbumIdIn(albums.map { it.id }) else emptyList()
+    }
+
+    private fun findAllByTagNameLikeLimit(tagNameLike: String, limit: Int) =
+        audioDao.findAllByTagIdIn(
+            tagDao.findAllByNameLikeLimit(tagNameLike, limit)
+                .map { it.id }
+        )
+}
\ No newline at end of file
diff --git a/src/main/kotlin/service/LoginService.kt b/src/main/kotlin/service/LoginService.kt
new file mode 100644
index 0000000..11a7f37
--- /dev/null
+++ b/src/main/kotlin/service/LoginService.kt
@@ -0,0 +1,26 @@
+/*
+ * Copyright (c) 2023. yo-saito. All Rights Reserved.
+ */
+
+package net.piedpiper.bremer.service
+
+import net.piedpiper.bremer.dao.UserDao
+import net.piedpiper.bremer.model.BremerUser
+import org.springframework.beans.factory.annotation.Qualifier
+import org.springframework.security.core.userdetails.UserDetails
+import org.springframework.security.core.userdetails.UserDetailsService
+import org.springframework.security.core.userdetails.UsernameNotFoundException
+import org.springframework.stereotype.Service
+import org.springframework.transaction.annotation.Transactional
+
+@Service("bremer.service.LoginService")
+class LoginService(
+    @Qualifier("bremer.dao.UserDao")
+    private val userDao: UserDao
+) : UserDetailsService {
+
+    @Transactional
+    override fun loadUserByUsername(name: String?): UserDetails? = name?.let {
+        userDao.findOneByName(name)?.let { BremerUser(it) }
+    } ?: throw UsernameNotFoundException("Login failed!")
+}
\ No newline at end of file
diff --git a/src/main/kotlin/service/PlaylistService.kt b/src/main/kotlin/service/PlaylistService.kt
new file mode 100644
index 0000000..560d216
--- /dev/null
+++ b/src/main/kotlin/service/PlaylistService.kt
@@ -0,0 +1,138 @@
+/*
+ * Copyright (c) 2023. yo-saito. All Rights Reserved.
+ */
+
+package net.piedpiper.bremer.service
+
+import net.piedpiper.bremer.dao.AudioDao
+import net.piedpiper.bremer.dao.PlaylistAudioDao
+import net.piedpiper.bremer.dao.PlaylistDao
+import net.piedpiper.bremer.entity.AudioEntity
+import net.piedpiper.bremer.entity.PlaylistAudioEntity
+import net.piedpiper.bremer.entity.PlaylistEntity
+import net.piedpiper.bremer.exception.BadRequestException
+import net.piedpiper.bremer.exception.NotFoundException
+import net.piedpiper.bremer.model.api.AllPlaylistResponse
+import net.piedpiper.bremer.model.api.PlaylistAudioRequest
+import net.piedpiper.bremer.model.api.PlaylistAudioResponse
+import net.piedpiper.bremer.model.api.PlaylistRequest
+import org.springframework.beans.factory.annotation.Qualifier
+import org.springframework.stereotype.Service
+import org.springframework.transaction.annotation.Transactional
+import java.util.*
+
+@Service("bremer.service.PlaylistService")
+class PlaylistService(
+    @Qualifier("bremer.dao.PlaylistDao")
+    private val playlistDao: PlaylistDao,
+    @Qualifier("bremer.dao.PlaylistAudioDao")
+    private val playlistAudioDao: PlaylistAudioDao,
+    @Qualifier("bremer.dao.AudioDao")
+    private val audioDao: AudioDao
+) {
+    @Transactional
+    fun getAllPlaylists(): AllPlaylistResponse =
+        AllPlaylistResponse(playlistDao.findAllOrderBySequence())
+
+    @Transactional
+    fun getPlaylist(slug: String): PlaylistAudioResponse = playlistDao.findOneBySlug(slug)
+        ?.let {
+            PlaylistAudioResponse(
+                playlistEntity = it,
+                audioEntityList = it?.playlistAudio
+                    ?.mapNotNull { it.audioId }
+                    ?.let { ids ->
+                        findAllByOrderedIds(ids)
+                    }
+            )
+        } ?: throw NotFoundException()
+
+    private fun findAllByOrderedIds(ids: List<Long>): List<AudioEntity> {
+        val id2idx = ids.mapIndexed { index, id -> id to index }.toMap()
+        return audioDao.findAllByIdIn(ids)
+            .sortedBy { id2idx[it.id] }
+    }
+
+    private fun findAllByOrderedSlugs(slugs: List<String>): List<AudioEntity> {
+        if (slugs.isEmpty()) {
+            return emptyList()
+        }
+        val slug2idx = slugs.mapIndexed { index, slug -> slug to index }.toMap()
+        return audioDao.findAllBySlugIn(slugs)
+            .sortedBy { slug2idx[it.slug] }
+    }
+
+    @Transactional
+    fun createPlaylist(request: PlaylistRequest) {
+        playlistDao.insertOne(
+            PlaylistEntity(
+                slug = UUID.randomUUID().toString(),
+                name = request.name
+            )
+        )
+    }
+
+    @Transactional
+    fun updatePlaylist(slug: String, request: PlaylistRequest) {
+        val entity = playlistDao.findOneBySlugWithLock(slug) ?: throw NotFoundException()
+        entity.name = request.name
+        playlistDao.updateOne(entity)
+    }
+
+    @Transactional
+    fun updatePlaylistAudioList(
+        slug: String,
+        request: PlaylistAudioRequest
+    ) {
+        playlistDao.findOneBySlug(slug)
+            ?.let { playlist ->
+                val audioList = findAllByOrderedSlugs(request.audioSlugs)
+                if (request.audioSlugs.size != audioList.size) {
+                    throw BadRequestException()
+                }
+                val registeredAudioIds = playlist.playlistAudio.map { it.audioId }.toSet()
+                val requestAudioIds = audioList.map { it.id }.toSet()
+                val playlistSize = playlist.playlistAudio?.size ?: 0
+
+                // delete
+                val deleteIds = playlist.playlistAudio
+                    .filter { !requestAudioIds.contains(it.audioId) }
+                    .map { it.id }
+                    .toList()
+                if (deleteIds.isNotEmpty()) {
+                    playlistAudioDao.deleteAllByIds(
+                        playlist.playlistAudio
+                            .filter { !requestAudioIds.contains(it.audioId) }
+                            .map { it.id }
+                            .toList()
+                    )
+                }
+                audioList.forEachIndexed { idx, audio ->
+                    if (registeredAudioIds.contains(audio.id)) {
+                        // ignore
+                        return@forEachIndexed
+                    }
+                    // add
+                    playlistAudioDao.insertOne(
+                        PlaylistAudioEntity(
+                            id = if (idx >= playlistSize) 0L else playlist?.playlistAudio!![idx].id,
+                            playlistId = playlist.id,
+                            sequence = idx,
+                            audioId = audio.id
+                        )
+                    )
+                }
+            } ?: throw NotFoundException()
+    }
+
+    private fun convertToPlaylistAudioResponse(entity: PlaylistEntity): PlaylistAudioResponse {
+        val audioList = entity?.playlistAudio?.mapNotNull { it.audioId }
+            ?.let {
+                findAllByOrderedIds(it)
+            } ?: emptyList()
+        return PlaylistAudioResponse(
+            playlistEntity = entity,
+            audioEntityList = audioList
+        )
+    }
+}
\ No newline at end of file
diff --git a/src/main/kotlin/service/TagService.kt b/src/main/kotlin/service/TagService.kt
new file mode 100644
index 0000000..4d5d70b
--- /dev/null
+++ b/src/main/kotlin/service/TagService.kt
@@ -0,0 +1,80 @@
+/*
+ * Copyright (c) 2023. yo-saito. All Rights Reserved.
+ */
+
+package net.piedpiper.bremer.service
+
+import net.piedpiper.bremer.dao.AudioDao
+import net.piedpiper.bremer.dao.AudioTagDao
+import net.piedpiper.bremer.dao.TagDao
+import net.piedpiper.bremer.entity.AudioTagEntity
+import net.piedpiper.bremer.entity.TagEntity
+import net.piedpiper.bremer.exception.NotFoundException
+import net.piedpiper.bremer.model.api.TagAudioRequest
+import net.piedpiper.bremer.model.api.TagAudioResponse
+import net.piedpiper.bremer.model.api.TagRequest
+import net.piedpiper.bremer.model.api.AllTagsResponse
+import org.springframework.beans.factory.annotation.Qualifier
+import org.springframework.stereotype.Service
+import java.util.*
+
+@Service("bremer.service.TagService")
+class TagService(
+    @Qualifier("bremer.dao.AudioDao")
+    private val audioDao: AudioDao,
+    @Qualifier("bremer.dao.AudioTagDao")
+    private val audioTagDao: AudioTagDao,
+    @Qualifier("bremer.dao.TagDao")
+    private val tagDao: TagDao
+) {
+    fun getAllTags(): AllTagsResponse = AllTagsResponse(tagDao.findAll())
+
+    fun createTag(request: TagRequest) {
+        tagDao.insertOne(TagEntity(slug = UUID.randomUUID().toString(), name = request.name))
+    }
+
+    fun updateTag(tagSlug: String, request: TagRequest) {
+        tagDao.findOneBySlugWithLock(tagSlug)
+            ?.let {
+                it.name = request.name
+                tagDao.updateOne(it)
+            } ?: throw NotFoundException()
+    }
+
+    fun getAudioListByTagSlug(tagSlug: String): TagAudioResponse =
+        tagDao.findOneBySlug(tagSlug)
+            ?.let { tag ->
+                TagAudioResponse(
+                    tag,
+                    audioDao.findAllByTagIdIn(listOf(tag.id))
+                )
+            } ?: throw NotFoundException()
+
+    fun addTagToAudioList(tagSlug: String, request: TagAudioRequest) {
+        tagDao.findOneBySlug(tagSlug)
+            ?.let { tag ->
+                audioDao.findAllBySlugIn(request.audioSlugs)
+                    .forEach { audio ->
+                        if (audioTagDao.findByAudioIdAndTagId(audio.id, tag.id) != null) {
+                            return@forEach
+                        }
+                        audioTagDao.insertOne(
+                            AudioTagEntity(
+                                audioId = audio.id,
+                                tagId = tag.id
+                            )
+                        )
+                    }
+            } ?: throw NotFoundException()
+    }
+
+    fun deleteTagFromAudioList(tagSlug: String, request: TagAudioRequest) {
+        tagDao.findOneBySlug(tagSlug)
+            ?.let { tag ->
+                audioDao.findAllBySlugIn(request.audioSlugs)
+                    .forEach { audio ->
+                        audioTagDao.deleteOneByAudioIdAndTagId(audio.id, tag.id)
+                    }
+            } ?: throw NotFoundException()
+    }
+}
\ No newline at end of file
diff --git a/src/main/kotlin/service/app/AudioAppService.kt b/src/main/kotlin/service/app/AudioAppService.kt
deleted file mode 100644
index 3729b42..0000000
--- a/src/main/kotlin/service/app/AudioAppService.kt
+++ /dev/null
@@ -1,61 +0,0 @@
-/*
- * Copyright (c) 2023. yo-saito. All Rights Reserved.
- */
-
-package net.piedpiper.bremer.service.app
-
-import net.piedpiper.bremer.entity.AudioPlayHistoryEntity
-import net.piedpiper.bremer.exception.NotFoundException
-import net.piedpiper.bremer.model.api.AudioListResponse
-import net.piedpiper.bremer.service.domain.AudioDomainService
-import org.springframework.beans.factory.annotation.Qualifier
-import org.springframework.stereotype.Service
-import org.springframework.transaction.annotation.Transactional
-import java.io.File
-import java.time.LocalDateTime
-import java.time.ZoneId
-
-@Service("bremer.service.AudioAppService")
-class AudioAppService(
-    @Qualifier("bremer.service.AudioDomainService")
-    private val audioDomainService: AudioDomainService,
-) {
-    companion object {
-        private const val PAGE_LIMIT = 50
-    }
-
-    @Transactional
-    fun getAudioFile(slug: String): File {
-        val audio = audioDomainService.findOneBySlug(slug) ?: throw NotFoundException()
-        val file = File(audio.path)
-        if (!file.exists()) {
-            throw NotFoundException()
-        }
-        audioDomainService.savePlayedHistory(
-            AudioPlayHistoryEntity(
-                audioId = audio.id,
-                lastPlayedAt = LocalDateTime.now(ZoneId.of("Asia/Tokyo"))
-            )
-        )
-        return file
-    }
-
-    @Transactional
-    fun getLeastRecentlyAccessedAudio(): AudioListResponse =
-        AudioListResponse(audioDomainService.findAllLruLimit(PAGE_LIMIT))
-
-    @Transactional
-    fun getByKeywords(
-        audioName: String?,
-        artistName: String?,
-        albumName: String?
-    ): AudioListResponse =
-        AudioListResponse(
-            audioDomainService.findAllByKeyword(
-                audioName,
-                artistName,
-                albumName,
-                PAGE_LIMIT
-            )
-        )
-}
\ No newline at end of file
diff --git a/src/main/kotlin/service/app/LoginAppService.kt b/src/main/kotlin/service/app/LoginAppService.kt
deleted file mode 100644
index 79ac208..0000000
--- a/src/main/kotlin/service/app/LoginAppService.kt
+++ /dev/null
@@ -1,28 +0,0 @@
-/*
- * Copyright (c) 2023. yo-saito. All Rights Reserved.
- */
-
-package net.piedpiper.bremer.service.app
-
-import net.piedpiper.bremer.model.api.BremerUser
-import net.piedpiper.bremer.service.domain.UserDomainService
-import org.springframework.beans.factory.annotation.Qualifier
-import org.springframework.security.core.userdetails.UserDetails
-import org.springframework.security.core.userdetails.UserDetailsService
-import org.springframework.security.core.userdetails.UsernameNotFoundException
-import org.springframework.security.crypto.password.PasswordEncoder
-import org.springframework.stereotype.Service
-import org.springframework.transaction.annotation.Transactional
-
-@Service("bremer.service.LoginAppService")
-class LoginAppService(
-    private val passwordEncoder: PasswordEncoder,
-    @Qualifier("bremer.dao.UserDomainService")
-    private val userDomainService: UserDomainService
-) : UserDetailsService {
-
-    @Transactional
-    override fun loadUserByUsername(name: String?): UserDetails? = name?.let {
-        userDomainService.findUserByName(name)?.let { BremerUser(it) }
-    } ?: throw UsernameNotFoundException("Login failed!")
-}
\ No newline at end of file
diff --git a/src/main/kotlin/service/app/PlaylistAppService.kt b/src/main/kotlin/service/app/PlaylistAppService.kt
deleted file mode 100644
index ab3e100..0000000
--- a/src/main/kotlin/service/app/PlaylistAppService.kt
+++ /dev/null
@@ -1,113 +0,0 @@
-/*
- * Copyright (c) 2023. yo-saito. All Rights Reserved.
- */
-
-package net.piedpiper.bremer.service.app
-
-import net.piedpiper.bremer.entity.PlaylistAudioEntity
-import net.piedpiper.bremer.entity.PlaylistEntity
-import net.piedpiper.bremer.exception.BadRequestException
-import net.piedpiper.bremer.exception.NotFoundException
-import net.piedpiper.bremer.model.PlaylistAudioResponse
-import net.piedpiper.bremer.model.PlaylistListResponse
-import net.piedpiper.bremer.model.PlaylistRequest
-import net.piedpiper.bremer.service.domain.AudioDomainService
-import net.piedpiper.bremer.service.domain.PlaylistDomainService
-import org.springframework.beans.factory.annotation.Qualifier
-import org.springframework.stereotype.Service
-import org.springframework.transaction.annotation.Transactional
-import java.util.UUID
-
-@Service("bremer.service.PlaylistAppService")
-class PlaylistAppService(
-    @Qualifier("bremer.service.PlaylistDomainService")
-    private val playlistDomainService: PlaylistDomainService,
-    @Qualifier("bremer.service.AudioDomainService")
-    private val audioDomainService: AudioDomainService
-) {
-    @Transactional
-    fun getAllPlaylists(): PlaylistListResponse =
-        PlaylistListResponse(playlistDomainService.findAll())
-
-    @Transactional
-    fun getPlaylist(slug: String): PlaylistAudioResponse =
-        convertToPlaylistAudioResponse(
-            playlistDomainService.findOneBySlug(slug) ?: throw NotFoundException()
-        )
-
-    @Transactional
-    fun createPlaylist(request: PlaylistRequest): PlaylistAudioResponse =
-        playlistDomainService.insertOne(
-            convertToPlaylistEntity(request)
-        ).let { entity ->
-            val audioList = entity?.playlistAudio?.mapNotNull { it.audioId }
-                ?.let {
-                    audioDomainService.findAllByOrderedIds(it)
-                } ?: emptyList()
-            PlaylistAudioResponse(
-                playlistEntity = entity,
-                audioEntityList = audioList
-            )
-        }
-
-    @Transactional
-    fun updatePlaylist(slug: String, request: PlaylistRequest): PlaylistAudioResponse =
-        playlistDomainService.findOneBySlug(slug)
-            ?.let { playlist ->
-                playlist.name = request.name
-                val audioList = audioDomainService.findAllByOrderedSlugs(request.audioSlugs)
-                if (request.audioSlugs.size != audioList.size) {
-                    throw BadRequestException()
-                }
-                val playlistSize = playlist.playlistAudio?.size ?: 0
-                playlist.playlistAudio = audioList.mapIndexed { idx, audio ->
-                    PlaylistAudioEntity(
-                        id = if (idx >= playlistSize) 0L else playlist?.playlistAudio!![idx].id,
-                        playlistId = playlist.id,
-                        sequence = idx,
-                        audioId = audio.id
-                    )
-                }
-                playlistDomainService.updateOne(
-                    playlist
-                ).let {
-                    PlaylistAudioResponse(
-                        playlistEntity = playlist,
-                        audioEntityList = audioList
-                    )
-                }
-            } ?: throw NotFoundException()
-
-    private fun convertToPlaylistEntity(
-        request: PlaylistRequest,
-        id: Long = 0L,
-        slug: String? = null
-    ): PlaylistEntity =
-        request.audioSlugs?.let {
-            audioDomainService.findAllByOrderedSlugs(it)
-        }?.associate { it.slug to it.id }
-            .let { audioIdMap ->
-                PlaylistEntity(
-                    id = id,
-                    slug = slug ?: UUID.randomUUID().toString(),
-                    name = request.name,
-                    playlistAudio = request.audioSlugs?.mapIndexed { idx, slug ->
-                        PlaylistAudioEntity(
-                            audioId = audioIdMap?.get(slug) ?: 0L,
-                            sequence = idx
-                        )
-                    } ?: emptyList()
-                )
-            }
-
-    private fun convertToPlaylistAudioResponse(entity: PlaylistEntity): PlaylistAudioResponse {
-        val audioList = entity?.playlistAudio?.mapNotNull { it.audioId }
-            ?.let {
-                audioDomainService.findAllByOrderedIds(it)
-            } ?: emptyList()
-        return PlaylistAudioResponse(
-            playlistEntity = entity,
-            audioEntityList = audioList
-        )
-    }
-}
\ No newline at end of file
diff --git a/src/main/kotlin/service/domain/AudioDomainService.kt b/src/main/kotlin/service/domain/AudioDomainService.kt
deleted file mode 100644
index 954c2d8..0000000
--- a/src/main/kotlin/service/domain/AudioDomainService.kt
+++ /dev/null
@@ -1,71 +0,0 @@
-/*
- * Copyright (c) 2023. yo-saito. All Rights Reserved.
- */
-
-package net.piedpiper.bremer.service.domain
-
-import net.piedpiper.bremer.config.Log
-import net.piedpiper.bremer.entity.AudioEntity
-import net.piedpiper.bremer.entity.AudioPlayHistoryEntity
-import net.piedpiper.bremer.repository.AudioRepository
-import org.springframework.beans.factory.annotation.Qualifier
-import org.springframework.stereotype.Service
-import org.springframework.transaction.annotation.Transactional
-
-@Service("bremer.service.AudioDomainService")
-class AudioDomainService(
-    @Qualifier("bremer.repository.AudioRepository")
-    private val audioRepository: AudioRepository,
-) {
-    private val log by Log()
-
-    @Transactional
-    fun findOneBySlug(slug: String): AudioEntity? {
-        val a = audioRepository.findOneBySlug(slug)
-        log.info("audio: {}", a)
-        return a
-    }
-
-    @Transactional
-    fun findAllByOrderedIds(ids: List<Long>): List<AudioEntity> {
-        val id2idx = ids.mapIndexed { index, id -> id to index }.toMap()
-        return audioRepository.findAllByIdIn(ids)
-            .sortedBy { id2idx[it.id] }
-    }
-
-    @Transactional
-    fun findAllByOrderedSlugs(slugs: List<String>): List<AudioEntity> {
-        if (slugs.isEmpty()) {
-            return emptyList()
-        }
-        val slug2idx = slugs.mapIndexed { index, slug -> slug to index }.toMap()
-        return audioRepository.findAllBySlugIn(slugs)
-            .sortedBy { slug2idx[it.slug] }
-    }
-
-    @Transactional
-    fun findAllLruLimit(limit: Int): List<AudioEntity> = audioRepository.findAllLruLimit(limit)
-
-    @Transactional
-    fun findAllByKeyword(
-        nameLike: String?,
-        artistNameLike: String?,
-        albumNameLike: String?,
-        limit: Int
-    ): List<AudioEntity> {
-        val set = mutableSetOf<AudioEntity>()
-        if (nameLike?.isNotEmpty() == true) {
-            set.addAll(audioRepository.findAllByNameLikeLimit(nameLike, limit))
-        }
-        if (artistNameLike?.isNotEmpty() == true) {
-            set.addAll(audioRepository.findAllByArtistNameLikeLimit(artistNameLike, limit))
-        }
-        if (albumNameLike?.isNotEmpty() == true) {
-            set.addAll(audioRepository.findAllByAlbumNameLikeLimit(albumNameLike, limit))
-        }
-        return set.take(limit).sortedByDescending { it.id }.toList()
-    }
-
-    fun savePlayedHistory(entity: AudioPlayHistoryEntity) =
-        audioRepository.saveAudioPlayHistory(entity)
-}
\ No newline at end of file
diff --git a/src/main/kotlin/service/domain/PlaylistDomainService.kt b/src/main/kotlin/service/domain/PlaylistDomainService.kt
deleted file mode 100644
index 75b25c2..0000000
--- a/src/main/kotlin/service/domain/PlaylistDomainService.kt
+++ /dev/null
@@ -1,32 +0,0 @@
-/*
- * Copyright (c) 2023. yo-saito. All Rights Reserved.
- */
-
-package net.piedpiper.bremer.service.domain
-
-import net.piedpiper.bremer.entity.PlaylistEntity
-import net.piedpiper.bremer.repository.PlaylistRepository
-import org.springframework.stereotype.Service
-import org.springframework.transaction.annotation.Transactional
-import java.util.*
-
-@Service("bremer.service.PlaylistDomainService")
-class PlaylistDomainService(
-    private val playlistRepository: PlaylistRepository
-) {
-    @Transactional
-    fun findAll(): List<PlaylistEntity> = playlistRepository.findAll()
-
-    @Transactional
-    fun findOneBySlug(slug: String): PlaylistEntity? = playlistRepository.findBySlug(slug)
-
-    @Transactional
-    fun insertOne(entity: PlaylistEntity): PlaylistEntity = playlistRepository.insertOne(entity)
-        .let { playlistRepository.findOneById(it) ?: throw IllegalStateException() }
-
-    @Transactional
-    fun updateOne(entity: PlaylistEntity): PlaylistEntity {
-        playlistRepository.updateOne(entity)
-        return playlistRepository.findOneById(entity.id) ?: throw IllegalStateException()
-    }
-}
\ No newline at end of file
diff --git a/src/main/kotlin/service/domain/UserDomainService.kt b/src/main/kotlin/service/domain/UserDomainService.kt
deleted file mode 100644
index cbed92d..0000000
--- a/src/main/kotlin/service/domain/UserDomainService.kt
+++ /dev/null
@@ -1,18 +0,0 @@
-/*
- * Copyright (c) 2023. yo-saito. All Rights Reserved.
- */
-
-package net.piedpiper.bremer.service.domain
-
-import net.piedpiper.bremer.entity.UserEntity
-import net.piedpiper.bremer.repository.UserRepository
-import org.springframework.beans.factory.annotation.Qualifier
-import org.springframework.stereotype.Service
-
-@Service("bremer.dao.UserDomainService")
-class UserDomainService(
-    @Qualifier("bremer.dao.UserRepository")
-    private val userRepository: UserRepository
-) {
-    fun findUserByName(name: String): UserEntity? = userRepository.findByName(name)
-}
\ No newline at end of file
diff --git a/src/main/resources/mapper/mapper.xml b/src/main/resources/mapper/mapper.xml
index c9d9730..675d93c 100644
--- a/src/main/resources/mapper/mapper.xml
+++ b/src/main/resources/mapper/mapper.xml
@@ -24,6 +24,12 @@
     <result property="name" column="name"/>
   </resultMap>
 
+  <resultMap id="AudioTagEntity" type="net.piedpiper.bremer.entity.AudioTagEntity">
+    <id property="id" column="id"/>
+    <result property="audioId" column="audio_id"/>
+    <result property="tagId" column="tag_id"/>
+  </resultMap>
+
   <resultMap id="AlbumEntity" type="net.piedpiper.bremer.entity.AlbumEntity">
     <id property="id" column="id"/>
     <result property="artistId" column="artist_id"/>
@@ -59,4 +65,10 @@
     <result property="name" column="name"/>
     <result property="secret" column="secret"/>
   </resultMap>
+
+  <resultMap id="TagEntity" type="net.piedpiper.bremer.entity.TagEntity">
+    <id property="id" column="id"/>
+    <result property="name" column="name"/>
+    <result property="slug" column="slug"/>
+  </resultMap>
 </mapper>