diff --git a/src/main/kotlin/goodspace/bllsoneshot/entity/assignment/Task.kt b/src/main/kotlin/goodspace/bllsoneshot/entity/assignment/Task.kt
index a70a8f3..cf5a0e7 100644
--- a/src/main/kotlin/goodspace/bllsoneshot/entity/assignment/Task.kt
+++ b/src/main/kotlin/goodspace/bllsoneshot/entity/assignment/Task.kt
@@ -7,6 +7,7 @@ import goodspace.bllsoneshot.global.exception.ExceptionMessage.NEGATIVE_ACTUAL_M
 import jakarta.persistence.*
 import org.hibernate.annotations.BatchSize
 import java.time.LocalDate
+import java.time.LocalDateTime
 
 @Entity
 class Task(
@@ -49,6 +50,9 @@ class Task(
 
     @Column(nullable = false)
     var completed: Boolean = false
+        protected set
+
+    var completedAt: LocalDate? = null
 
     @get:Transient
     val questions: List<Comment>
@@ -84,6 +88,11 @@ class Task(
         proofShots.forEach { it.markFeedbackAsRead() }
     }
 
+    fun markAsCompleted(date: LocalDate) {
+        completed = true
+        completedAt = date
+    }
+
     // TODO: 로직 이해하기
     //  피드백 재저장 시, 기존 FEEDBACK 타입 Comment만 삭제하고 QUESTION은 보존한다.
     //  Comment는 task.comments와 proofShot.comments 양쪽에 참조되어 있으므로,
diff --git a/src/main/kotlin/goodspace/bllsoneshot/entity/user/User.kt b/src/main/kotlin/goodspace/bllsoneshot/entity/user/User.kt
index c04e464..4fe540e 100644
--- a/src/main/kotlin/goodspace/bllsoneshot/entity/user/User.kt
+++ b/src/main/kotlin/goodspace/bllsoneshot/entity/user/User.kt
@@ -1,6 +1,7 @@
 package goodspace.bllsoneshot.entity.user
 
 import goodspace.bllsoneshot.entity.BaseEntity
+import jakarta.persistence.CascadeType
 import jakarta.persistence.Column
 import jakarta.persistence.Entity
 import jakarta.persistence.EnumType
@@ -33,12 +34,9 @@ class User(
     @Column(columnDefinition = "MEDIUMBLOB")
     val profileImage: ByteArray? = null
 ) : BaseEntity() {
-    @OneToMany(mappedBy = "mentee", fetch = FetchType.LAZY)
+    @OneToMany(mappedBy = "mentee", fetch = FetchType.LAZY, cascade = [CascadeType.ALL])
     val subjects: MutableList<MenteeSubject> = mutableListOf()
 
-    @OneToMany(mappedBy = "mentee", fetch = FetchType.LAZY)
-    val reports: MutableList<LearningReport> = mutableListOf()
-
     var refreshToken: String? = null
 
     var fcmToken: String? = null
diff --git a/src/main/kotlin/goodspace/bllsoneshot/global/init/UserInitializer.kt b/src/main/kotlin/goodspace/bllsoneshot/global/init/UserInitializer.kt
index 2387fc3..34849b0 100644
--- a/src/main/kotlin/goodspace/bllsoneshot/global/init/UserInitializer.kt
+++ b/src/main/kotlin/goodspace/bllsoneshot/global/init/UserInitializer.kt
@@ -1,5 +1,7 @@
 package goodspace.bllsoneshot.global.init
 
+import goodspace.bllsoneshot.entity.assignment.Subject
+import goodspace.bllsoneshot.entity.user.MenteeSubject
 import goodspace.bllsoneshot.entity.user.User
 import goodspace.bllsoneshot.entity.user.UserRole
 import goodspace.bllsoneshot.entity.user.UserRole.ROLE_MENTEE
@@ -89,6 +91,13 @@ class UserInitializer(
             profileImage = profileImage
         )
 
+        val subjects = listOf(
+            MenteeSubject(user, Subject.KOREAN),
+            MenteeSubject(user, Subject.ENGLISH),
+            MenteeSubject(user, Subject.MATH),
+        )
+        user.subjects.addAll(subjects)
+
         return userRepository.save(user)
     }
 
diff --git a/src/main/kotlin/goodspace/bllsoneshot/mentor/service/MentorDashboardService.kt b/src/main/kotlin/goodspace/bllsoneshot/mentor/service/MentorDashboardService.kt
index b8d4558..30c579d 100644
--- a/src/main/kotlin/goodspace/bllsoneshot/mentor/service/MentorDashboardService.kt
+++ b/src/main/kotlin/goodspace/bllsoneshot/mentor/service/MentorDashboardService.kt
@@ -85,9 +85,9 @@ class MentorDashboardService(
             .toSet()
 
         val recentTaskByMenteeId = taskRepository
-            .findMostRecentTasksByMenteeIds(menteeIds)
+            .findMostRecentTaskByMenteeIds(menteeIds)
             .groupBy { it.mentee.id!! }
-            .mapValues { (_, tasks) -> tasks.first() }
+            .mapValues { (_, tasks) -> tasks.first() } // completedAt DESC이므로 first가 가장 최근
 
         val menteeDetails = mentees.map { mentee ->
             val recentTask = recentTaskByMenteeId[mentee.id]
diff --git a/src/main/kotlin/goodspace/bllsoneshot/repository/task/TaskRepository.kt b/src/main/kotlin/goodspace/bllsoneshot/repository/task/TaskRepository.kt
index 718dce9..ad503a9 100644
--- a/src/main/kotlin/goodspace/bllsoneshot/repository/task/TaskRepository.kt
+++ b/src/main/kotlin/goodspace/bllsoneshot/repository/task/TaskRepository.kt
@@ -10,6 +10,7 @@ import goodspace.bllsoneshot.notification.dto.response.UnfinishedTaskCountRespon
 import java.time.LocalDate
 import org.springframework.data.jpa.repository.JpaRepository
 import org.springframework.data.jpa.repository.Query
+import org.springframework.data.repository.query.Param
 
 interface TaskRepository : JpaRepository<Task, Long> {
 
@@ -160,18 +161,16 @@ interface TaskRepository : JpaRepository<Task, Long> {
 
     @Query(
         """
-        SELECT t FROM Task t
-        WHERE t.mentee.id IN :menteeIds
-        AND t.isResource = false
-        AND t.date = (
-            SELECT MAX(t2.date) FROM Task t2
-            WHERE t2.mentee = t.mentee
-            AND t2.isResource = false
-        )
-        ORDER BY t.mentee.id, t.id DESC
-        """
+    SELECT t FROM Task t
+    WHERE t.mentee.id IN :menteeIds
+    AND t.isResource = false
+    AND t.completedAt IS NOT NULL
+    ORDER BY t.completedAt DESC
+    """
     )
-    fun findMostRecentTasksByMenteeIds(menteeIds: List<Long>): List<Task>
+    fun findMostRecentTaskByMenteeIds(
+        @Param("menteeIds") menteeIds: List<Long>
+    ): List<Task>
 
     @Query(
         """
diff --git a/src/main/kotlin/goodspace/bllsoneshot/task/service/TaskService.kt b/src/main/kotlin/goodspace/bllsoneshot/task/service/TaskService.kt
index e4b73ea..1e3d7f2 100644
--- a/src/main/kotlin/goodspace/bllsoneshot/task/service/TaskService.kt
+++ b/src/main/kotlin/goodspace/bllsoneshot/task/service/TaskService.kt
@@ -193,7 +193,7 @@ class TaskService(
         validateTaskCompletable(task, request.currentDate)
 
         task.actualMinutes = request.actualMinutes
-        task.completed = true
+        task.markAsCompleted(request.currentDate)
     }
 
     @Transactional
@@ -322,10 +322,6 @@ class TaskService(
         val task = taskRepository.findById(taskId)
             .orElseThrow { IllegalArgumentException(TASK_NOT_FOUND.message) }
 
-        if (task.isResource) {
-            throw IllegalArgumentException(TASK_NOT_FOUND.message)
-        }
-
         return task
     }