diff --git a/src/main/java/com/kuit/chatdiary/controller/DiaryController.java b/src/main/java/com/kuit/chatdiary/controller/DiaryController.java
index 04158ac4..2919cb48 100644
--- a/src/main/java/com/kuit/chatdiary/controller/DiaryController.java
+++ b/src/main/java/com/kuit/chatdiary/controller/DiaryController.java
@@ -34,7 +34,7 @@ public class DiaryController {
 
 
     @GetMapping("/detail")
-    public ResponseEntity<DiaryShowDetailResponseDTO> showDiary(@RequestParam(name="user_id") Long userId, @RequestParam(name="diary_date") Date diaryDate) throws ParseException, ParseException {
+    public ResponseEntity<DiaryShowDetailResponseDTO> showDiary(@RequestParam(name="user_id") Long userId, @RequestParam(name="diary_date") Date diaryDate) throws Exception {
         log.info("[DiaryController.showDiary]");
 
         return ResponseEntity.ok().body(diaryService.showDiary(userId,diaryDate));
diff --git a/src/main/java/com/kuit/chatdiary/dto/diary/DiaryShowDetailResponseDTO.java b/src/main/java/com/kuit/chatdiary/dto/diary/DiaryShowDetailResponseDTO.java
index 7b4e2419..c0d101c6 100644
--- a/src/main/java/com/kuit/chatdiary/dto/diary/DiaryShowDetailResponseDTO.java
+++ b/src/main/java/com/kuit/chatdiary/dto/diary/DiaryShowDetailResponseDTO.java
@@ -19,12 +19,12 @@ public class DiaryShowDetailResponseDTO {
 
     private String title;
 
-    //private String imgUrl;
     private List<String> imgUrl;
 
     private String content;
 
-    //private String tagName;
     private List<String> tagName;
 
+    private Long CharacterIndex;
+
 }
diff --git a/src/main/java/com/kuit/chatdiary/repository/DiaryRepository.java b/src/main/java/com/kuit/chatdiary/repository/DiaryRepository.java
index 061f6710..d01d25bd 100644
--- a/src/main/java/com/kuit/chatdiary/repository/DiaryRepository.java
+++ b/src/main/java/com/kuit/chatdiary/repository/DiaryRepository.java
@@ -8,10 +8,14 @@
 import jakarta.persistence.EntityManager;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
+import org.springframework.http.HttpStatus;
+import org.springframework.http.ResponseEntity;
 import org.springframework.stereotype.Repository;
+import org.springframework.web.server.ResponseStatusException;
 
 import java.text.ParseException;
 import java.text.SimpleDateFormat;
+import java.util.ArrayList;
 import java.util.Date;
 import java.util.List;
 
@@ -22,7 +26,7 @@ public class DiaryRepository {
 
     private final EntityManager em;
 
-    public DiaryShowDetailResponseDTO showDiaryDetail (Long userId, java.sql.Date diaryDate) {
+    public DiaryShowDetailResponseDTO showDiaryDetail (Long userId, java.sql.Date diaryDate) throws Exception {
 
         log.info("[DiaryRepository.showDiaryDetail]");
 
@@ -33,12 +37,17 @@ public DiaryShowDetailResponseDTO showDiaryDetail (Long userId, java.sql.Date di
         List<Object[]> resultList = em.createQuery("SELECT d.diaryId, d.title, d.content FROM diary d WHERE d.member.userId = :user_id AND d.diaryDate = :diary_date")
                 .setParameter("user_id", userId).setParameter("diary_date", diaryDate).getResultList();
 
+        if(resultList.size()==0){
+            throw new ResponseStatusException(HttpStatus.NOT_FOUND);
+        }
+
         for(Object[] result : resultList){
             diaryId = (Long) result[0];
             title = (String) result[1];
             content = (String) result[2];
         }
 
+
         List<String> imageUrlList =  em.createQuery("SELECT p.imageUrl FROM diaryphoto dp LEFT OUTER JOIN dp.photo p"+
                 " WHERE dp.diary.diaryId = :diary_id").setParameter("diary_id", diaryId).getResultList();
 
@@ -47,8 +56,18 @@ public DiaryShowDetailResponseDTO showDiaryDetail (Long userId, java.sql.Date di
                         " WHERE dt.diary.id = :diary_id")
                 .setParameter("diary_id", diaryId).getResultList();
 
+        List<Object[]> senderCounts = em.createQuery("SELECT c.sender, MAX(c.createAt) AS latest_created_at, COUNT(*) AS cnt FROM chat c"+
+                        " WHERE DATE(c.createAt) = : diary_date AND c.sender NOT IN :user"+
+                        " GROUP BY c.sender ORDER BY cnt DESC, latest_created_at DESC")
+                .setParameter("diary_date", diaryDate).setParameter("user", Sender.USER).getResultList();
+
+        if(senderCounts.size()==0){
+            return new DiaryShowDetailResponseDTO(diaryDate, title, imageUrlList, content, tagNameList, null);
+        }
+
+        Sender sender = (Sender) senderCounts.get(0)[0];
+        return new DiaryShowDetailResponseDTO(diaryDate, title, imageUrlList, content, tagNameList, (long) sender.getIndex());
 
-        return new DiaryShowDetailResponseDTO(diaryDate, title, imageUrlList, content, tagNameList);
 
     }
 
@@ -64,6 +83,7 @@ public Long findDiaryId(DiaryModifyRequestDTO diaryModifyRequestDTO) throws Pars
         List<Long> resultList = em.createQuery("SELECT d.diaryId FROM diary d WHERE d.member.userId = :user_id AND d.diaryDate = :diary_date")
                 .setParameter("user_id", diaryModifyRequestDTO.getUserId()).setParameter("diary_date",diaryDate).getResultList();
 
+
         for(Long result : resultList){
             diaryId = result;
         }
diff --git a/src/main/java/com/kuit/chatdiary/service/DiaryService.java b/src/main/java/com/kuit/chatdiary/service/DiaryService.java
index b4526e84..5aee8fbf 100644
--- a/src/main/java/com/kuit/chatdiary/service/DiaryService.java
+++ b/src/main/java/com/kuit/chatdiary/service/DiaryService.java
@@ -10,6 +10,7 @@
 import com.kuit.chatdiary.repository.DiaryRepository;
 import lombok.RequiredArgsConstructor;
 import lombok.extern.slf4j.Slf4j;
+import org.springframework.http.ResponseEntity;
 import org.springframework.stereotype.Service;
 import org.springframework.transaction.annotation.Transactional;
 import org.springframework.web.multipart.MultipartFile;
@@ -32,7 +33,7 @@ public class DiaryService {
 
     private final S3Uploader s3Uploader;
 
-    public DiaryShowDetailResponseDTO showDiary(Long userId, Date diaryDate) throws ParseException {
+    public DiaryShowDetailResponseDTO showDiary(Long userId, Date diaryDate) throws Exception {
         log.info("[DiaryService.showDiary]");
         return diaryRepository.showDiaryDetail(userId, diaryDate);
     }