diff --git a/rog/management/commands/check_user_auth.py b/rog/management/commands/check_user_auth.py
new file mode 100644
index 0000000..92e87b2
--- /dev/null
+++ b/rog/management/commands/check_user_auth.py
@@ -0,0 +1,36 @@
+from django.core.management.base import BaseCommand
+from rog.models import CustomUser
+from django.contrib.auth import authenticate
+
+class Command(BaseCommand):
+    help = 'Check user authentication'
+
+    def add_arguments(self, parser):
+        parser.add_argument('email', type=str, help='User email to check')
+        parser.add_argument('--password', type=str, help='Password to test', default='')
+
+    def handle(self, *args, **options):
+        email = options['email']
+        password = options.get('password', '')
+        
+        self.stdout.write(f'Checking user: {email}')
+        
+        try:
+            user = CustomUser.objects.get(email=email)
+            self.stdout.write(f'✅ User found: {user.email}')
+            self.stdout.write(f'   Active: {user.is_active}')
+            self.stdout.write(f'   Has password: {bool(user.password)}')
+            self.stdout.write(f'   Password hash start: {user.password[:30]}...')
+            
+            if password:
+                self.stdout.write(f'\n🔐 Testing authentication with provided password...')
+                auth_user = authenticate(username=email, password=password)
+                if auth_user:
+                    self.stdout.write('✅ Authentication successful')
+                else:
+                    self.stdout.write('❌ Authentication failed')
+                    
+        except CustomUser.DoesNotExist:
+            self.stdout.write(f'❌ User does not exist: {email}')
+        except Exception as e:
+            self.stdout.write(f'❌ Error: {e}')
diff --git a/rog/serializers.py b/rog/serializers.py
index ef90f00..b2d1fdd 100755
--- a/rog/serializers.py
+++ b/rog/serializers.py
@@ -535,9 +535,10 @@ class LoginUserSerializer(serializers.Serializer):
             else:
                 # Check if the user exists
                 try:
-                    user_obj = User.objects.get(email=email)
+                    from .models import CustomUser
+                    user_obj = CustomUser.objects.get(email=email)
                     raise serializers.ValidationError("Incorrect password.")
-                except User.DoesNotExist:
+                except CustomUser.DoesNotExist:
                     raise serializers.ValidationError("User with this email does not exist.")
         else:
             raise serializers.ValidationError("Must include 'email' and 'password'.")
diff --git a/rog/views.py b/rog/views.py
index 1c8d7df..cbbdd3b 100755
--- a/rog/views.py
+++ b/rog/views.py
@@ -908,11 +908,14 @@ class LoginAPI(generics.GenericAPIView):
     def post(self, request, *args, **kwargs):
         logger.info(f"Login attempt for identifier: {request.data.get('identifier', 'identifier not provided')}")
         logger.debug(f"Request data: {request.data}")
+        logger.debug(f"Request headers: {dict(request.headers)}")
 
         # フロントエンドの 'identifier' フィールドを 'email' にマッピング
         data = request.data.copy()
         if 'identifier' in data and 'email' not in data:
             data['email'] = data['identifier']
+        
+        logger.debug(f"Processed data: {data}")
 
         serializer = self.get_serializer(data=data)
         try: