diff --git a/popcorn/Assets/MyGame/Scripts/HeaderManager.cs b/popcorn/Assets/MyGame/Scripts/HeaderManager.cs
index 5e91eda4..ba596a1c 100644
--- a/popcorn/Assets/MyGame/Scripts/HeaderManager.cs
+++ b/popcorn/Assets/MyGame/Scripts/HeaderManager.cs
@@ -21,43 +21,16 @@ public class HeaderManager : MonoBehaviour
         });
         missionButton.OnClickAsObservable().ThrottleFirst(TimeSpan.FromSeconds(1f)).Subscribe(_ =>
         {
-            MissionManager.ShowDialog(onAchieved:() => missionIndicator.SetActive(CheckMissionIndicate()));
+            MissionManager.ShowDialog();
         });
         informationButton.OnClickAsObservable().ThrottleFirst(TimeSpan.FromSeconds(1f)).Subscribe(_ =>
         {
             TransitionManager.Instance.LoadSceneAdditive(GameScenes.Information);
         });
         // mission報酬通知
-        missionIndicator.SetActive(CheckMissionIndicate());
-    }
-
-    private bool CheckMissionIndicate()
-    {
-        // ミッション読み込み
-        var missionList = SpreadsheetDataManager.Instance.GetBaseDataList<MissionData>(Const.MissionDataSheet);
-        var gameData = GameDataManager.GameData;
-        // ミッション表示
-        if (missionList
-            .Where(data => data.Category == MissionCategory.Normal && data.shopLevel <= gameData.ViewedShopLevel)
-            .Where(missionData => !GameDataManager.GameData.AchievedMission.Contains(missionData.id))
-            .Any(missionData => missionData.count <= MissionManager.GetProgressValue(missionData)))
+        GameDataObserver.Instance.UpdateMissionAchieved.Subscribe(x =>
         {
-            return true;
-        }
-
-        // dailyMission
-        // コンプリートミッション
-        if (!gameData.dailyMissionCompleted)
-        {
-            if (gameData.dailyMissionIdArray.Length <= gameData.dailyMissionAchievedIdArray.Length)
-            {
-                return true;
-            }
-        }
-
-        var ids = gameData.dailyMissionIdArray.Except(gameData.dailyMissionAchievedIdArray);
-        return missionList
-            .Where(data => ids.Contains(data.id))
-            .Any(missionData => missionData.count <= MissionManager.GetDailyProgressValue(missionData));
+            missionIndicator.SetActive(x);
+        }).AddTo(this);
     }
 }