diff --git a/backend/src/main/java/com/example/todoapp/controller/ToBuysController.java b/backend/src/main/java/com/example/todoapp/controller/ToBuysController.java
index 196f8a8..03c7e30 100644
--- a/backend/src/main/java/com/example/todoapp/controller/ToBuysController.java
+++ b/backend/src/main/java/com/example/todoapp/controller/ToBuysController.java
@@ -57,19 +57,36 @@ public class ToBuysController {
      */
 
     @PostMapping("/add")
-    public ResponseEntity<String> addToBuys(
+    public ResponseEntity<Map<String, Object>> addToBuys(
         @Valid @RequestBody ToBuysDTO dto, 
         Authentication authentication) {
-        toBuysService.addToBuys(dto, authentication);
-        return ResponseEntity.ok("Item added to 'To Buys' successfully");
+            
+        ToBuys createdToBuy = toBuysService.addToBuys(dto, authentication);
+            
+        // 构建响应体
+        Map<String, Object> response = new HashMap<>();
+        response.put("result", true);
+        response.put("tobuyId", createdToBuy.getTobuyId());
+        response.put("stuffId", createdToBuy.getStuff().getStuffId());
+        response.put("message", "追加に成功しました");
+            
+        return ResponseEntity.ok(response);
     }
 
     @PutMapping("/update")
-    public ResponseEntity<String> updateToBuys(
+    public ResponseEntity<Map<String, Object>> updateToBuys(
         @Valid @RequestBody ToBuysDTO dto, 
         Authentication authentication) {
         toBuysService.updateToBuys(dto, authentication);
-        return ResponseEntity.ok("Item updated to 'To Buys' successfully");
+
+        ToBuys updatedToBuy = toBuysService.updateToBuys(dto, authentication);
+
+
+        Map<String, Object> response = new HashMap<>();
+        response.put("tobuyId", updatedToBuy.getTobuyId());
+        response.put("stuffId", updatedToBuy.getStuff().getStuffId());
+        
+        return ResponseEntity.ok(response);
     }
 
 
diff --git a/backend/src/main/java/com/example/todoapp/repository/StuffsRepository.java b/backend/src/main/java/com/example/todoapp/repository/StuffsRepository.java
index 6edbc88..1bd452f 100644
--- a/backend/src/main/java/com/example/todoapp/repository/StuffsRepository.java
+++ b/backend/src/main/java/com/example/todoapp/repository/StuffsRepository.java
@@ -10,6 +10,7 @@ package com.example.todoapp.repository;
 
 import com.example.todoapp.model.Stuffs;
 
+import java.util.Optional;
 
 import org.springframework.data.jpa.repository.JpaRepository;
 import org.springframework.stereotype.Repository;
@@ -26,4 +27,6 @@ public interface StuffsRepository extends JpaRepository<Stuffs, Long> {
     // 材料情報を主キーで取得するメソッド（必要に応じて追加）
     Stuffs findByStuffId(Long stuffId);
 
+    Optional<Stuffs> findByStuffName(String stuffName);
+
 }
\ No newline at end of file
diff --git a/backend/src/main/java/com/example/todoapp/service/ToBuysService.java b/backend/src/main/java/com/example/todoapp/service/ToBuysService.java
index 0908e01..54ef18e 100644
--- a/backend/src/main/java/com/example/todoapp/service/ToBuysService.java
+++ b/backend/src/main/java/com/example/todoapp/service/ToBuysService.java
@@ -62,7 +62,7 @@ public class ToBuysService {
      *
      * @param toBuyDTO 追加する購入アイテムのデータ（DTO）
      */
-    public void addToBuys(ToBuysDTO toBuyDTO, Authentication authentication) {
+    public ToBuys addToBuys(ToBuysDTO toBuyDTO, Authentication authentication) {
 
         // ユーザー情報を取得
         String username = authentication.getName();
@@ -92,8 +92,8 @@ public class ToBuysService {
         toBuys.setStore(toBuyDTO.getShop());
 
         // データベースに保存
-        toBuysRepository.save(toBuys);
-
+        return toBuysRepository.save(toBuys);
+        
     }
 
     /**
@@ -101,7 +101,7 @@ public class ToBuysService {
      *
      * @param toBuyDTO 変更する購入アイテムのデータ（DTO）
      */
-    public void updateToBuys(ToBuysDTO toBuyDTO, Authentication authentication) {
+    public ToBuys  updateToBuys(ToBuysDTO toBuyDTO, Authentication authentication) {
 
         // ユーザー情報を取得
         String username = authentication.getName();
@@ -110,11 +110,20 @@ public class ToBuysService {
 
         Stuffs stuffs;
         if (toBuyDTO.getStuffId() == null) {
+
+            Optional<Stuffs> existingStuffs = stuffsRepository.findByStuffName(toBuyDTO.getStuffName());
             // 新しい材料を作成
-            stuffs = new Stuffs();
-            stuffs.setStuffName(toBuyDTO.getStuffName());
-            stuffs.setCategory(toBuyDTO.getCategory());
-            stuffs = stuffsRepository.save(stuffs); 
+            if (existingStuffs.isPresent()) {
+                // 如果存在，更新已有材料的属性
+                stuffs = existingStuffs.get();
+                stuffs.setCategory(toBuyDTO.getCategory()); // 可选：更新分类
+            } else {
+                // 否则新建材料
+                stuffs = new Stuffs();
+                stuffs.setStuffName(toBuyDTO.getStuffName());
+                stuffs.setCategory(toBuyDTO.getCategory());
+            }
+            stuffsRepository.save(stuffs);
         } else {
             // 材料情報を取得
             Optional<Stuffs> optionalStuffs = stuffsRepository.findById(toBuyDTO.getStuffId());
@@ -124,22 +133,18 @@ public class ToBuysService {
             stuffs = optionalStuffs.get();    
             
             //update
-            // stuffs.setStuffName(toBuyDTO.getStuffName());
-            // stuffs.setCategory(toBuyDTO.getCategory());
             stuffs = stuffsRepository.save(stuffs);
         }
 
-
-
         ToBuys toBuys = new ToBuys();
+        toBuys.setTobuyId(toBuyDTO.getTobuyId());
         toBuys.setUser(user);
         toBuys.setStuff(stuffs);
         toBuys.setAmount(toBuyDTO.getAmount());
         toBuys.setStore(toBuyDTO.getShop());
 
         // データベースに保存
-        toBuysRepository.save(toBuys);
-
+        return toBuysRepository.save(toBuys);
     }
 
     /**