diff --git a/src/main/java/icu/samnyan/aqua/sega/aimedb/handler/Impl/RegisterHandler.java b/src/main/java/icu/samnyan/aqua/sega/aimedb/handler/Impl/RegisterHandler.java
index db9732f8..4a53ac10 100644
--- a/src/main/java/icu/samnyan/aqua/sega/aimedb/handler/Impl/RegisterHandler.java
+++ b/src/main/java/icu/samnyan/aqua/sega/aimedb/handler/Impl/RegisterHandler.java
@@ -52,7 +52,11 @@ public class RegisterHandler implements BaseHandler {
         if(cardRepository.findByLuid((String) requestMap.get("luid")).isEmpty()) {
             Card card = new Card();
             card.setLuid((String) requestMap.get("luid"));
-            card.setExtId(ThreadLocalRandom.current().nextLong(99999999));
+            int extId = ThreadLocalRandom.current().nextInt(99999999);
+            while (cardRepository.findByExtId(extId).isPresent()) {
+                extId = ThreadLocalRandom.current().nextInt(99999999);
+            }
+            card.setExtId(extId);
             card.setRegisterTime(LocalDateTime.now());
             card.setAccessTime(LocalDateTime.now());
 
diff --git a/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserActivityRepository.java b/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserActivityRepository.java
index 67800990..0aa45744 100644
--- a/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserActivityRepository.java
+++ b/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserActivityRepository.java
@@ -16,5 +16,5 @@ public interface UserActivityRepository extends JpaRepository<UserActivity, Long
 
     Optional<UserActivity> findTopByUserAndActivityIdAndKindOrderByIdDesc(UserData user, int activityId, int kind);
 
-    List<UserActivity> findAllByUser_Card_ExtIdAndKindOrderBySortNumberDesc(long extId, int kind);
+    List<UserActivity> findAllByUser_Card_ExtIdAndKindOrderBySortNumberDesc(int extId, int kind);
 }
diff --git a/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserDataRepository.java b/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserDataRepository.java
index 03bb98ab..0ef17fe8 100644
--- a/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserDataRepository.java
+++ b/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserDataRepository.java
@@ -15,5 +15,5 @@ public interface UserDataRepository extends JpaRepository<UserData, Long> {
 
     Optional<UserData> findByCard(Card card);
 
-    Optional<UserData> findByCard_ExtId(long extId);
+    Optional<UserData> findByCard_ExtId(int extId);
 }
diff --git a/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserDuelRepository.java b/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserDuelRepository.java
index 69b45e3d..a695e9a2 100644
--- a/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserDuelRepository.java
+++ b/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserDuelRepository.java
@@ -16,5 +16,5 @@ public interface UserDuelRepository extends JpaRepository<UserDuel, Long> {
 
     Optional<UserDuel> findTopByUserAndDuelIdOrderByIdDesc(UserData user, int duelId);
 
-    List<UserDuel> findByUser_Card_ExtId(long extId);
+    List<UserDuel> findByUser_Card_ExtId(int extId);
 }
diff --git a/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserGameOptionExRepository.java b/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserGameOptionExRepository.java
index 4423dcd1..668846ca 100644
--- a/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserGameOptionExRepository.java
+++ b/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserGameOptionExRepository.java
@@ -14,5 +14,5 @@ import java.util.Optional;
 public interface UserGameOptionExRepository extends JpaRepository<UserGameOptionEx, Long> {
     Optional<UserGameOptionEx> findByUser(UserData user);
 
-    Optional<UserGameOptionEx> findByUser_Card_ExtId(long parseLong);
+    Optional<UserGameOptionEx> findByUser_Card_ExtId(int extId);
 }
diff --git a/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserGameOptionRepository.java b/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserGameOptionRepository.java
index 1c070489..349e14f7 100644
--- a/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserGameOptionRepository.java
+++ b/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserGameOptionRepository.java
@@ -15,5 +15,5 @@ public interface UserGameOptionRepository extends JpaRepository<UserGameOption,
 
     Optional<UserGameOption> findByUser(UserData user);
 
-    Optional<UserGameOption> findByUser_Card_ExtId(long extId);
+    Optional<UserGameOption> findByUser_Card_ExtId(int extId);
 }
diff --git a/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserItemRepository.java b/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserItemRepository.java
index 3301186a..fd020fdb 100644
--- a/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserItemRepository.java
+++ b/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserItemRepository.java
@@ -17,5 +17,5 @@ public interface UserItemRepository extends JpaRepository<UserItem, Long> {
 
     Optional<UserItem> findTopByUserAndItemIdAndItemKindOrderByIdDesc(UserData user, int itemId, int itemKind);
 
-    Page<UserItem> findAllByUser_Card_ExtIdAndItemKind(long extId, int itemKind, Pageable pageable);
+    Page<UserItem> findAllByUser_Card_ExtIdAndItemKind(int extId, int itemKind, Pageable pageable);
 }
diff --git a/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserMapRepository.java b/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserMapRepository.java
index cad3484b..cb84c269 100644
--- a/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserMapRepository.java
+++ b/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserMapRepository.java
@@ -15,7 +15,7 @@ import java.util.Optional;
 public interface UserMapRepository extends JpaRepository<UserMap, Long> {
     List<UserMap> findAllByUser(UserData user);
 
-    List<UserMap> findAllByUser_Card_ExtId(long extId);
+    List<UserMap> findAllByUser_Card_ExtId(int extId);
 
     Optional<UserMap> findTopByUserAndMapIdOrderByIdDesc(UserData user, int mapId);
 }
diff --git a/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserMusicDetailRepository.java b/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserMusicDetailRepository.java
index e5520bf4..71a826cd 100644
--- a/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserMusicDetailRepository.java
+++ b/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserMusicDetailRepository.java
@@ -18,7 +18,7 @@ public interface UserMusicDetailRepository extends JpaRepository<UserMusicDetail
 
     Optional<UserMusicDetail> findTopByUserAndMusicIdAndLevelOrderByIdDesc(UserData user, int musicId, int level);
 
-    List<UserMusicDetail> findByUser_Card_ExtId(long parseLong);
+    List<UserMusicDetail> findByUser_Card_ExtId(int extId);
 
-    Page<UserMusicDetail> findByUser_Card_ExtId(long aimeId, Pageable page);
+    Page<UserMusicDetail> findByUser_Card_ExtId(int extId, Pageable page);
 }
diff --git a/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserPlaylogRepository.java b/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserPlaylogRepository.java
index f44f6f4a..b0bd91d0 100644
--- a/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserPlaylogRepository.java
+++ b/src/main/java/icu/samnyan/aqua/sega/chunithm/dao/userdata/UserPlaylogRepository.java
@@ -12,7 +12,7 @@ import java.util.List;
  */
 @Repository
 public interface UserPlaylogRepository extends JpaRepository<UserPlaylog, Long> {
-    List<UserPlaylog> findByUser_Card_ExtIdAndLevelNot(long extId, int levelNot, Pageable page);
+    List<UserPlaylog> findByUser_Card_ExtIdAndLevelNot(int extId, int levelNot, Pageable page);
 
-    List<UserPlaylog> findByUser_Card_ExtId(long parseLong, Pageable page);
+    List<UserPlaylog> findByUser_Card_ExtId(int extId, Pageable page);
 }
diff --git a/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserActivityService.java b/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserActivityService.java
index 82b43def..89ab754d 100644
--- a/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserActivityService.java
+++ b/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserActivityService.java
@@ -35,6 +35,6 @@ public class UserActivityService {
     }
 
     public List<UserActivity> getAllByUserIdAndKind(String userId, String kind) {
-        return userActivityRepository.findAllByUser_Card_ExtIdAndKindOrderBySortNumberDesc(Long.parseLong(userId), Integer.parseInt(kind));
+        return userActivityRepository.findAllByUser_Card_ExtIdAndKindOrderBySortNumberDesc(Integer.parseInt(userId), Integer.parseInt(kind));
     }
 }
diff --git a/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserCharacterService.java b/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserCharacterService.java
index 09b2795d..b7869463 100644
--- a/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserCharacterService.java
+++ b/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserCharacterService.java
@@ -43,6 +43,6 @@ public class UserCharacterService {
 
     public Page<UserCharacter> getByUser(String userId, int pageNumber, int maxCount) {
         Pageable pageable = PageRequest.of(pageNumber, maxCount);
-        return userCharacterRepository.findByUser_Card_ExtId(Long.parseLong(userId), pageable);
+        return userCharacterRepository.findByUser_Card_ExtId(Integer.parseInt(userId), pageable);
     }
 }
diff --git a/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserChargeService.java b/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserChargeService.java
index a4386525..3eba8d86 100644
--- a/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserChargeService.java
+++ b/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserChargeService.java
@@ -25,7 +25,7 @@ public class UserChargeService {
     }
 
     public List<UserCharge> getByUserId(String userId) {
-        return userChargeRepository.findByUser_Card_ExtId(Long.parseLong(userId));
+        return userChargeRepository.findByUser_Card_ExtId(Integer.parseInt(userId));
     }
 
     public Optional<UserCharge> getByUserAndChargeId(UserData user, String chargeId) {
diff --git a/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserCourseService.java b/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserCourseService.java
index 875cbf0b..6eed7cb8 100644
--- a/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserCourseService.java
+++ b/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserCourseService.java
@@ -38,11 +38,11 @@ public class UserCourseService {
     }
 
     public List<UserCourse> getByUser(String userId) {
-        return userCourseRepository.findByUser_Card_ExtId(Long.parseLong(userId));
+        return userCourseRepository.findByUser_Card_ExtId(Integer.parseInt(userId));
     }
 
     public Page<UserCourse> getByUser(String userId, int pageNum, int maxCount) {
         Pageable page = PageRequest.of(pageNum, maxCount);
-        return userCourseRepository.findByUser_Card_ExtId(Long.parseLong(userId), page);
+        return userCourseRepository.findByUser_Card_ExtId(Integer.parseInt(userId), page);
     }
 }
diff --git a/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserDataExService.java b/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserDataExService.java
index 904a52fb..aaeeef37 100644
--- a/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserDataExService.java
+++ b/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserDataExService.java
@@ -30,6 +30,6 @@ public class UserDataExService {
     }
 
     public Optional<UserDataEx> getUserByExtId(String userId) {
-        return userDataExRepository.findByUser_Card_ExtId(Long.parseLong(userId));
+        return userDataExRepository.findByUser_Card_ExtId(Integer.parseInt(userId));
     }
 }
diff --git a/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserDataService.java b/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserDataService.java
index fdfb4214..c6f43da8 100644
--- a/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserDataService.java
+++ b/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserDataService.java
@@ -22,7 +22,7 @@ public class UserDataService {
     }
 
     public Optional<UserData> getUserByExtId(String aimeId) {
-        return userDataRepository.findByCard_ExtId(Long.parseLong(aimeId));
+        return userDataRepository.findByCard_ExtId(Integer.parseInt(aimeId));
     }
 
     public String updateLoginTime(UserData userData) {
diff --git a/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserDuelService.java b/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserDuelService.java
index ddfb1728..c2c9aa17 100644
--- a/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserDuelService.java
+++ b/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserDuelService.java
@@ -35,7 +35,7 @@ public class UserDuelService {
     }
 
     public List<UserDuel> getByUser(String userId) {
-        return userDuelRepository.findByUser_Card_ExtId(Long.parseLong(userId));
+        return userDuelRepository.findByUser_Card_ExtId(Integer.parseInt(userId));
     }
 
 }
diff --git a/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserGameOptionExService.java b/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserGameOptionExService.java
index 0c704879..7601aef2 100644
--- a/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserGameOptionExService.java
+++ b/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserGameOptionExService.java
@@ -30,6 +30,6 @@ public class UserGameOptionExService {
     }
 
     public Optional<UserGameOptionEx> getByUserId(String userId) {
-        return userGameOptionExRepository.findByUser_Card_ExtId(Long.parseLong(userId));
+        return userGameOptionExRepository.findByUser_Card_ExtId(Integer.parseInt(userId));
     }
 }
diff --git a/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserGameOptionService.java b/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserGameOptionService.java
index c3b09471..ab5dd50e 100644
--- a/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserGameOptionService.java
+++ b/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserGameOptionService.java
@@ -22,7 +22,7 @@ public class UserGameOptionService {
     }
 
     public Optional<UserGameOption> getByUserId(String userId) {
-        return userGameOptionRepository.findByUser_Card_ExtId(Long.parseLong(userId));
+        return userGameOptionRepository.findByUser_Card_ExtId(Integer.parseInt(userId));
     }
 
     public Optional<UserGameOption> getByUser(UserData user) {
diff --git a/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserItemService.java b/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserItemService.java
index 932f2547..ab706fd6 100644
--- a/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserItemService.java
+++ b/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserItemService.java
@@ -39,6 +39,6 @@ public class UserItemService {
 
     public Page<UserItem> getByUserAndItemKind(String userId, int kind, int pageNumber, int maxCount) {
         Pageable page = PageRequest.of(pageNumber, maxCount);
-        return userItemRepository.findAllByUser_Card_ExtIdAndItemKind(Long.parseLong(userId), kind, page);
+        return userItemRepository.findAllByUser_Card_ExtIdAndItemKind(Integer.parseInt(userId), kind, page);
     }
 }
diff --git a/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserMapService.java b/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserMapService.java
index b9a0a0b1..4e1e5071 100644
--- a/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserMapService.java
+++ b/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserMapService.java
@@ -27,7 +27,7 @@ public class UserMapService {
     }
 
     public List<UserMap> getByUser(String userId) {
-        return userMapRepository.findAllByUser_Card_ExtId(Long.parseLong(userId));
+        return userMapRepository.findAllByUser_Card_ExtId(Integer.parseInt(userId));
     }
 
     public Optional<UserMap> getByUserAndMapId(UserData user, String mapId) {
diff --git a/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserMusicDetailService.java b/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserMusicDetailService.java
index 03bd7515..8f950b41 100644
--- a/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserMusicDetailService.java
+++ b/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserMusicDetailService.java
@@ -38,11 +38,11 @@ public class UserMusicDetailService {
     }
 
     public List<UserMusicDetail> getByUser(String userId) {
-        return userMusicDetailRepository.findByUser_Card_ExtId(Long.parseLong(userId));
+        return userMusicDetailRepository.findByUser_Card_ExtId(Integer.parseInt(userId));
     }
 
     public Page<UserMusicDetail> getByUser(String userId, int pageNum, int maxCount) {
         Pageable page = PageRequest.of(pageNum, maxCount);
-        return userMusicDetailRepository.findByUser_Card_ExtId(Long.parseLong(userId), page);
+        return userMusicDetailRepository.findByUser_Card_ExtId(Integer.parseInt(userId), page);
     }
 }
diff --git a/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserPlaylogService.java b/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserPlaylogService.java
index 09ce1e10..5fc579d0 100644
--- a/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserPlaylogService.java
+++ b/src/main/java/icu/samnyan/aqua/sega/chunithm/service/UserPlaylogService.java
@@ -33,11 +33,11 @@ public class UserPlaylogService {
 
     public List<UserPlaylog> getRecent30Plays(String userId) {
         Pageable page = PageRequest.of(0, 30, Sort.by(Sort.Direction.DESC, "userPlayDate"));
-        return userPlaylogRepository.findByUser_Card_ExtIdAndLevelNot(Long.parseLong(userId), 4, page);
+        return userPlaylogRepository.findByUser_Card_ExtIdAndLevelNot(Integer.parseInt(userId), 4, page);
     }
 
     public List<UserPlaylog> getRecentPlays(String userId) {
         Pageable page = PageRequest.of(0, 50, Sort.by(Sort.Direction.DESC, "userPlayDate"));
-        return userPlaylogRepository.findByUser_Card_ExtId(Long.parseLong(userId), page);
+        return userPlaylogRepository.findByUser_Card_ExtId(Integer.parseInt(userId), page);
     }
 }
diff --git a/src/main/java/icu/samnyan/aqua/sega/general/dao/CardRepository.java b/src/main/java/icu/samnyan/aqua/sega/general/dao/CardRepository.java
index 416d1c8b..2128f6bd 100644
--- a/src/main/java/icu/samnyan/aqua/sega/general/dao/CardRepository.java
+++ b/src/main/java/icu/samnyan/aqua/sega/general/dao/CardRepository.java
@@ -12,7 +12,7 @@ import java.util.Optional;
 @Repository("SegaCardRepository")
 public interface CardRepository extends JpaRepository<Card, Long> {
 
-    Optional<Card> findByExtId(long extId);
+    Optional<Card> findByExtId(int extId);
 
     Optional<Card> findByLuid(String luid);
 }
diff --git a/src/main/java/icu/samnyan/aqua/sega/general/model/Card.java b/src/main/java/icu/samnyan/aqua/sega/general/model/Card.java
index 954bcb91..2b2daa57 100644
--- a/src/main/java/icu/samnyan/aqua/sega/general/model/Card.java
+++ b/src/main/java/icu/samnyan/aqua/sega/general/model/Card.java
@@ -26,7 +26,7 @@ public class Card implements Serializable {
 
     // A external id
     @Column(name = "ext_id", unique = true)
-    private long extId;
+    private Integer extId;
 
     // Access Code
     @Column(unique = true)
diff --git a/src/main/java/icu/samnyan/aqua/sega/general/service/CardService.java b/src/main/java/icu/samnyan/aqua/sega/general/service/CardService.java
index f13952d0..61112337 100644
--- a/src/main/java/icu/samnyan/aqua/sega/general/service/CardService.java
+++ b/src/main/java/icu/samnyan/aqua/sega/general/service/CardService.java
@@ -21,6 +21,6 @@ public class CardService {
     }
 
     public Optional<Card> getCardByExtId(String extId) {
-        return cardRepository.findByExtId(Long.parseLong(extId));
+        return cardRepository.findByExtId(Integer.parseInt(extId));
     }
 }