diff --git a/src/main/kotlin/dev/usbharu/hideout/query/FollowerQueryService.kt b/src/main/kotlin/dev/usbharu/hideout/query/FollowerQueryService.kt
new file mode 100644
index 00000000..3ca4e4e6
--- /dev/null
+++ b/src/main/kotlin/dev/usbharu/hideout/query/FollowerQueryService.kt
@@ -0,0 +1,12 @@
+package dev.usbharu.hideout.query
+
+import dev.usbharu.hideout.domain.model.hideout.entity.User
+
+interface FollowerQueryService {
+    suspend fun findFollowersById(id: Long): List<User>
+    suspend fun findFollowersByNameAndDomain(name: String, domain: String): List<User>
+    suspend fun findFollowingById(id: Long): List<User>
+    suspend fun findFollowingByNameAndDomain(name: String, domain: String): List<User>
+    suspend fun appendFollower(user: Long, follower: Long)
+    suspend fun removeFollower(user: Long, follower: Long)
+}
diff --git a/src/main/kotlin/dev/usbharu/hideout/query/FollowerQueryServiceImpl.kt b/src/main/kotlin/dev/usbharu/hideout/query/FollowerQueryServiceImpl.kt
new file mode 100644
index 00000000..ffcb1ccc
--- /dev/null
+++ b/src/main/kotlin/dev/usbharu/hideout/query/FollowerQueryServiceImpl.kt
@@ -0,0 +1,201 @@
+package dev.usbharu.hideout.query
+
+import dev.usbharu.hideout.domain.model.hideout.entity.User
+import dev.usbharu.hideout.repository.Users
+import dev.usbharu.hideout.repository.UsersFollowers
+import org.jetbrains.exposed.sql.*
+import org.jetbrains.exposed.sql.SqlExpressionBuilder.eq
+import java.time.Instant
+
+class FollowerQueryServiceImpl : FollowerQueryService {
+    override suspend fun findFollowersById(id: Long): List<User> {
+        val followers = Users.alias("FOLLOWERS")
+        return Users.innerJoin(
+            otherTable = UsersFollowers,
+            onColumn = { Users.id },
+            otherColumn = { userId }
+        )
+            .innerJoin(
+                otherTable = followers,
+                onColumn = { UsersFollowers.followerId },
+                otherColumn = { followers[Users.id] }
+            )
+            .slice(
+                followers[Users.id],
+                followers[Users.name],
+                followers[Users.domain],
+                followers[Users.screenName],
+                followers[Users.description],
+                followers[Users.password],
+                followers[Users.inbox],
+                followers[Users.outbox],
+                followers[Users.url],
+                followers[Users.publicKey],
+                followers[Users.privateKey],
+                followers[Users.createdAt]
+            )
+            .select { Users.id eq id }
+            .map {
+                User(
+                    id = it[followers[Users.id]],
+                    name = it[followers[Users.name]],
+                    domain = it[followers[Users.domain]],
+                    screenName = it[followers[Users.screenName]],
+                    description = it[followers[Users.description]],
+                    password = it[followers[Users.password]],
+                    inbox = it[followers[Users.inbox]],
+                    outbox = it[followers[Users.outbox]],
+                    url = it[followers[Users.url]],
+                    publicKey = it[followers[Users.publicKey]],
+                    privateKey = it[followers[Users.privateKey]],
+                    createdAt = Instant.ofEpochMilli(it[followers[Users.createdAt]])
+                )
+            }
+    }
+
+    override suspend fun findFollowersByNameAndDomain(name: String, domain: String): List<User> {
+        val followers = Users.alias("FOLLOWERS")
+        return Users.innerJoin(
+            otherTable = UsersFollowers,
+            onColumn = { Users.id },
+            otherColumn = { userId }
+        )
+            .innerJoin(
+                otherTable = followers,
+                onColumn = { UsersFollowers.followerId },
+                otherColumn = { followers[Users.id] }
+            )
+            .slice(
+                followers[Users.id],
+                followers[Users.name],
+                followers[Users.domain],
+                followers[Users.screenName],
+                followers[Users.description],
+                followers[Users.password],
+                followers[Users.inbox],
+                followers[Users.outbox],
+                followers[Users.url],
+                followers[Users.publicKey],
+                followers[Users.privateKey],
+                followers[Users.createdAt]
+            )
+            .select { Users.name eq name and (Users.domain eq domain) }
+            .map {
+                User(
+                    id = it[followers[Users.id]],
+                    name = it[followers[Users.name]],
+                    domain = it[followers[Users.domain]],
+                    screenName = it[followers[Users.screenName]],
+                    description = it[followers[Users.description]],
+                    password = it[followers[Users.password]],
+                    inbox = it[followers[Users.inbox]],
+                    outbox = it[followers[Users.outbox]],
+                    url = it[followers[Users.url]],
+                    publicKey = it[followers[Users.publicKey]],
+                    privateKey = it[followers[Users.privateKey]],
+                    createdAt = Instant.ofEpochMilli(it[followers[Users.createdAt]])
+                )
+            }
+    }
+
+    override suspend fun findFollowingById(id: Long): List<User> {
+        val followers = Users.alias("FOLLOWERS")
+        return Users.innerJoin(
+            otherTable = UsersFollowers,
+            onColumn = { Users.id },
+            otherColumn = { userId }
+        )
+            .innerJoin(
+                otherTable = followers,
+                onColumn = { UsersFollowers.followerId },
+                otherColumn = { followers[Users.id] }
+            )
+            .slice(
+                followers[Users.id],
+                followers[Users.name],
+                followers[Users.domain],
+                followers[Users.screenName],
+                followers[Users.description],
+                followers[Users.password],
+                followers[Users.inbox],
+                followers[Users.outbox],
+                followers[Users.url],
+                followers[Users.publicKey],
+                followers[Users.privateKey],
+                followers[Users.createdAt]
+            )
+            .select { followers[Users.id] eq id }
+            .map {
+                User(
+                    id = it[followers[Users.id]],
+                    name = it[followers[Users.name]],
+                    domain = it[followers[Users.domain]],
+                    screenName = it[followers[Users.screenName]],
+                    description = it[followers[Users.description]],
+                    password = it[followers[Users.password]],
+                    inbox = it[followers[Users.inbox]],
+                    outbox = it[followers[Users.outbox]],
+                    url = it[followers[Users.url]],
+                    publicKey = it[followers[Users.publicKey]],
+                    privateKey = it[followers[Users.privateKey]],
+                    createdAt = Instant.ofEpochMilli(it[followers[Users.createdAt]])
+                )
+            }
+    }
+
+    override suspend fun findFollowingByNameAndDomain(name: String, domain: String): List<User> {
+        val followers = Users.alias("FOLLOWERS")
+        return Users.innerJoin(
+            otherTable = UsersFollowers,
+            onColumn = { Users.id },
+            otherColumn = { userId }
+        )
+            .innerJoin(
+                otherTable = followers,
+                onColumn = { UsersFollowers.followerId },
+                otherColumn = { followers[Users.id] }
+            )
+            .slice(
+                followers[Users.id],
+                followers[Users.name],
+                followers[Users.domain],
+                followers[Users.screenName],
+                followers[Users.description],
+                followers[Users.password],
+                followers[Users.inbox],
+                followers[Users.outbox],
+                followers[Users.url],
+                followers[Users.publicKey],
+                followers[Users.privateKey],
+                followers[Users.createdAt]
+            )
+            .select { followers[Users.name] eq name and (followers[Users.domain] eq domain) }
+            .map {
+                User(
+                    id = it[followers[Users.id]],
+                    name = it[followers[Users.name]],
+                    domain = it[followers[Users.domain]],
+                    screenName = it[followers[Users.screenName]],
+                    description = it[followers[Users.description]],
+                    password = it[followers[Users.password]],
+                    inbox = it[followers[Users.inbox]],
+                    outbox = it[followers[Users.outbox]],
+                    url = it[followers[Users.url]],
+                    publicKey = it[followers[Users.publicKey]],
+                    privateKey = it[followers[Users.privateKey]],
+                    createdAt = Instant.ofEpochMilli(it[followers[Users.createdAt]])
+                )
+            }
+    }
+
+    override suspend fun appendFollower(user: Long, follower: Long) {
+        UsersFollowers.insert {
+            it[userId] = user
+            it[followerId] = follower
+        }
+    }
+
+    override suspend fun removeFollower(user: Long, follower: Long) {
+        UsersFollowers.deleteWhere { Users.id eq user and (followerId eq follower) }
+    }
+}