diff --git a/mashup-member/src/main/java/kr/mashup/branding/facade/mashong/MashongFacadeService.java b/mashup-member/src/main/java/kr/mashup/branding/facade/mashong/MashongFacadeService.java
index 1798cd8b..345ea3e1 100644
--- a/mashup-member/src/main/java/kr/mashup/branding/facade/mashong/MashongFacadeService.java
+++ b/mashup-member/src/main/java/kr/mashup/branding/facade/mashong/MashongFacadeService.java
@@ -14,6 +14,9 @@
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 
+import java.time.LocalDate;
+import java.time.temporal.ChronoUnit;
+
 @Service
 @RequiredArgsConstructor
 public class MashongFacadeService {
@@ -149,4 +152,12 @@ public PlatformMashongStatusResponse readCurrentStatus(Long memberGenerationId)
 
         return PlatformMashongStatusResponse.of(platformMashong, mashongPopcorn);
     }
+
+    @Transactional(readOnly = true)
+    public Long withMashongDaysCount(Long memberGenerationId) {
+        LocalDate now = LocalDate.now();
+        MemberGeneration memberGeneration = memberService.findByMemberGenerationId(memberGenerationId);
+        LocalDate generationStartedAt = memberGeneration.getGeneration().getStartedAt();
+        return ChronoUnit.DAYS.between(generationStartedAt, now);
+    }
 }
diff --git a/mashup-member/src/main/java/kr/mashup/branding/ui/mashong/MashongController.java b/mashup-member/src/main/java/kr/mashup/branding/ui/mashong/MashongController.java
index c264a1f7..475fb77f 100644
--- a/mashup-member/src/main/java/kr/mashup/branding/ui/mashong/MashongController.java
+++ b/mashup-member/src/main/java/kr/mashup/branding/ui/mashong/MashongController.java
@@ -89,4 +89,11 @@ public ApiResponse<PlatformMashongStatusResponse> readStatus(@ApiIgnore MemberAu
         PlatformMashongStatusResponse result = mashongFacadeService.readCurrentStatus(memberAuth.getMemberGenerationId());
         return ApiResponse.success(result);
     }
+
+    @ApiOperation(value = "매숑이와 함께한 날 Days count")
+    @GetMapping("/with-mashong-days")
+    public ApiResponse<Long> withMashongDays(@ApiIgnore MemberAuth memberAuth) {
+        Long withMashongDays = mashongFacadeService.withMashongDaysCount(memberAuth.getMemberGenerationId());
+        return ApiResponse.success(withMashongDays);
+    }
 }