diff --git a/tools/legacy-db-migration/README.md b/tools/legacy-db-migration/README.md
index 1a65aeda..a31a1fae 100644
--- a/tools/legacy-db-migration/README.md
+++ b/tools/legacy-db-migration/README.md
@@ -92,19 +92,26 @@ apply. It also refuses a changed host/database/user identity or a source table
 whose maximum ID moved behind its checkpoint. Password rotation does not change
 the source fingerprint.
 
-| Source data                                   | Incremental policy                                                      |
-| --------------------------------------------- | ----------------------------------------------------------------------- |
-| `member_log`                                  | Read only IDs after the committed high-water mark.                      |
-| game archive/event-history tables             | Read only IDs after the profile checkpoint.                             |
-| `member`, root/game `storage`, `system`, bans | Rescan and idempotently upsert because old rows are mutable.            |
-| `ng_games`                                    | Rescan because a season row can gain its final winner after creation.   |
-| preserved `batres<general_no>.txt` seasons    | Hash each season; import new immutable seasons after a full checkpoint. |
+| Source data                                | Incremental policy                                                      |
+| ------------------------------------------ | ----------------------------------------------------------------------- |
+| `member_log`                               | Read only IDs after the committed high-water mark.                      |
+| game archive/event-history tables          | Read only IDs after the profile checkpoint.                             |
+| `member`, root `storage`, `system`, bans   | Rescan and idempotently upsert because old rows are mutable.            |
+| game `storage`                             | Rescan by `(namespace, key)` and refresh a recreated row's source ID.   |
+| `ng_games`                                 | Rescan because a season row can gain its final winner after creation.   |
+| preserved `batres<general_no>.txt` seasons | Hash each season; import new immutable seasons after a full checkpoint. |
 
 The append policy assumes Ref primary keys are never reused and completed
 archive rows are immutable. Incremental mode does not mirror source deletions.
 If either assumption is false, take a new reviewed backup and run full mode;
 do not edit checkpoint rows by hand.
 
+Ref may delete and recreate a mutable game-storage tuple with the same
+`(namespace, key)` and a new auto-increment ID. That tuple is the durable
+identity; the latest source ID is retained only as recovery metadata. Rows for
+deleted tuples remain archived because incremental mode does not infer
+tombstones.
+
 The optional file importer reads only immediate
 `logs/preserved/<profile>_*/batres<general_no>.txt` regular files. It maps the
 profile and season directory to the archived general's `(source_profile,
diff --git a/tools/legacy-db-migration/src/game.ts b/tools/legacy-db-migration/src/game.ts
index d897d7da..784f6b2c 100644
--- a/tools/legacy-db-migration/src/game.ts
+++ b/tools/legacy-db-migration/src/game.ts
@@ -504,7 +504,9 @@ const migrateStorage = async (
             }
         }
         if (target) {
-            await upsertRows(target, 'legacy_game_storage', archives, ['source_id']);
+            // Ref storage는 같은 namespace/key를 삭제 후 새 auto-increment ID로 다시 만들 수 있다.
+            // 장기 상태의 권위 identity로 자연키를 사용하고 최신 source ID까지 함께 갱신한다.
+            await upsertRows(target, 'legacy_game_storage', archives, ['namespace', 'key']);
             await upsertRows(target, 'inheritance_point', points, ['user_id', 'key']);
             await upsertRows(target, 'inheritance_user_state', userStates, ['user_id']);
         }
diff --git a/tools/legacy-db-migration/test/game.test.ts b/tools/legacy-db-migration/test/game.test.ts
index 79b86ef4..df780d91 100644
--- a/tools/legacy-db-migration/test/game.test.ts
+++ b/tools/legacy-db-migration/test/game.test.ts
@@ -30,6 +30,14 @@ const sourceRows = {
             data: JSON.stringify({ leader: 80, power: 70, intel: 60, history: 'first<br>second<br>' }),
         },
     ],
+    storage: [
+        {
+            id: 12,
+            namespace: 'inheritance_42',
+            key: 'point',
+            value: '[30,null]',
+        },
+    ],
 } satisfies Record<string, Array<Record<string, unknown>>>;
 
 const sourcePool = (): MariaPool => {
@@ -148,6 +156,8 @@ describe('legacy archive game migration', () => {
         expect(summary.importRunId).toBe('77');
         expect(sql).toContain('INSERT INTO "legacy_archive"."game_history"');
         expect(sql).toContain('INSERT INTO "legacy_archive"."general"');
+        expect(sql).toContain('INSERT INTO "legacy_game_storage"');
+        expect(sql).toContain('ON CONFLICT ("namespace", "key")');
         expect(sql).not.toContain('INSERT INTO "ng_games"');
         expect(sql).not.toContain('INSERT INTO "ng_old_generals"');
         expect(sql).toContain(`SET "status" = 'COMPLETED'`);