diff --git a/.github/workflows/sync-upstream.yml b/.github/workflows/sync-upstream.yml
index 0a7d5fee1..4fdc0390e 100644
--- a/.github/workflows/sync-upstream.yml
+++ b/.github/workflows/sync-upstream.yml
@@ -18,7 +18,7 @@ jobs:
         with:
           repository: ${{ github.repository }}
           token: ${{ secrets.GITHUB_TOKEN }}
-          fetch-depth: 0  # 모든 히스토리 가져오기
+          fetch-depth: 0
 
       - name: Configure Git
         run: |
@@ -28,276 +28,121 @@ jobs:
       - name: Add Upstream Remote
         run: |
           git remote add upstream https://github.com/react-hook-form/documentation
-          git fetch upstream
+          git fetch upstream --prune --tags --depth=1000000
+          git fetch origin --prune
 
-      - name: Checkout and Set Up Master Branch
+      - name: Detect Upstream Changes
+        id: detect
         run: |
-          git checkout -B master origin/master
+          if git diff --quiet origin/master..upstream/master -- . ':(exclude).github'; then
+            echo "has_changes=false" >> $GITHUB_ENV
+          else
+            echo "has_changes=true" >> $GITHUB_ENV
+          fi
+          echo "Detected changes between origin/master and upstream/master"
+          echo "master_changed=false" >> $GITHUB_ENV
+          echo "master_ko_changed=false" >> $GITHUB_ENV
 
-      # ***********************
-      #   충돌 자동 해결을 위해 -X theirs 추가
-      # ***********************
-      - name: Merge Upstream/master into master
+      - name: Update master branch
+        if: env.has_changes == 'true'
         run: |
-          # 업스트림 변경을 우선으로(충돌 발생 시 upstream/master 변경사항 사용)
+          set -euo pipefail
+          git checkout -B master origin/master
           git merge upstream/master -X theirs --no-edit
 
-          # .github 및 .vscode 디렉토리 삭제
           for DIR in .github .vscode; do
             git rm -r --cached "$DIR" || true
             rm -rf "$DIR"
           done
 
-          # .gitignore 유지
           git checkout --ours .gitignore || true
-
-          # 변경 사항 스테이징
-          git add .
-
-          # 로그 출력: 현재 스테이지에 있는 파일
-          echo "Staged files:"
-          git diff --cached --name-only
-
-          # 변경 사항이 있을 경우에만 커밋
-          git commit -m "Sync with upstream (remove .github & .vscode, keep .gitignore)" || echo "No changes to commit"
-        shell: bash
-
-      - name: Check for Changes
-        id: changes
-        run: |
-          # .github 디렉토리 제외한 변경 사항 확인
-          git diff upstream/master master -- . ':(exclude).github' > changes.diff
-          if [ -s changes.diff ]; then
-            echo "changes=true" >> $GITHUB_ENV
-          else
-            echo "changes=false" >> $GITHUB_ENV
-          fi
-          echo "Changes detected (excluding .github):"
-          cat changes.diff
-        shell: bash
-
-      - name: Check Existing PRs for Master Sync
-        id: existing-prs
-        run: |
-          RESPONSE=$(curl -s \
-              -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" \
-              -H "Accept: application/vnd.github.v3+json" \
-              https://api.github.com/repos/${{ github.repository }}/pulls)
-          EXISTING_PR=$(echo "$RESPONSE" | jq -r '.[] | select(.head.ref | startswith("sync-upstream-")) | .head.ref' | tr '\n' ' ')
-          if [[ -n "$EXISTING_PR" ]]; then
-              echo "existing_pr=true" >> $GITHUB_ENV
-              echo "existing_pr_ref=$EXISTING_PR" >> $GITHUB_ENV
+          git add -A
+          if git diff --cached --quiet; then
+            echo "master_changed=false" >> $GITHUB_ENV
           else
-              echo "existing_pr=false" >> $GITHUB_ENV
+            git commit -m "Sync with upstream (remove .github & .vscode, keep .gitignore)"
+            echo "master_changed=true" >> $GITHUB_ENV
           fi
-          echo "Existing PRs for master sync: $EXISTING_PR"
-        shell: bash
 
-      - name: Compare Changes with Existing PRs for Master Sync
-        id: compare-changes
-        if: env.existing_pr == 'true' && env.changes == 'true'
+      - name: Push master branch
+        if: env.master_changed == 'true'
         run: |
-          ALL_EXISTING_INCLUDED=true
-          for pr_ref in ${{ env.existing_pr_ref }}
-          do
-            echo "Fetching branch: $pr_ref"
-            git fetch origin "$pr_ref:$pr_ref-branch"
+          git push origin master
 
-            echo "Comparing with upstream/master excluding .github"
-            if ! git diff --quiet upstream/master "$pr_ref-branch" -- . ':(exclude).github'; then
-              ALL_EXISTING_INCLUDED=false
-              break
-            fi
-          done
-
-          if [ "$ALL_EXISTING_INCLUDED" = true ]; then
-            echo "diff=false" >> $GITHUB_ENV
-          else
-            echo "diff=true" >> $GITHUB_ENV
-
-            # 기존 PR 닫기
-            for pr_ref in ${{ env.existing_pr_ref }}
-            do
-              PR_NUMBER=$(curl -s \
-                -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" \
-                -H "Accept: application/vnd.github.v3+json" \
-                https://api.github.com/repos/${{ github.repository }}/pulls \
-                | jq -r '.[] | select(.head.ref=="'$pr_ref'") | .number')
-              echo "Closing PR #$PR_NUMBER"
-              curl -X PATCH \
-                -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" \
-                -H "Accept: application/vnd.github.v3+json" \
-                https://api.github.com/repos/${{ github.repository }}/pulls/$PR_NUMBER \
-                -d '{"state":"closed"}'
-            done
-          fi
-        shell: bash
+      # ===== master-ko 업데이트 =====
 
-      - name: Create Pull Request for Master Sync
-        if: env.diff == 'true' || env.existing_pr == 'false'
+      - name: Check Existing master-ko PR
+        id: find-ko-pr
         run: |
-          # 새로운 브랜치 생성
-          BRANCH_NAME=sync-upstream-$(date +%Y%m%d%H%M%S)
-          git checkout -b $BRANCH_NAME
-
-          # 브랜치 푸시
-          git push origin $BRANCH_NAME
-
-          # PR 생성
-          curl -X POST \
+          RESPONSE=$(curl -s \
             -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" \
             -H "Accept: application/vnd.github.v3+json" \
-            https://api.github.com/repos/${{ github.repository }}/pulls \
-            -d '{
-              "title": "Sync with upstream (removing .github directory)",
-              "body": "This PR syncs the repository with upstream changes and removes the entire .github directory.",
-              "head": "'"${BRANCH_NAME}"'",
-              "base": "master"
-            }'
-        shell: bash
-
-      # ===== master-ko 업데이트 파트 =====
-
-      - name: Check Existing PRs for master-ko Update
-        id: existing-prs-ko
-        run: |
-          RESPONSE=$(curl -s \
-              -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" \
-              -H "Accept: application/vnd.github.v3+json" \
-              "https://api.github.com/repos/${{ github.repository }}/pulls")
-          EXISTING_KO_PR=$(echo "$RESPONSE" | jq -r '.[] | select(.head.ref | startswith("update-master-ko-")) | .head.ref' | tr '\n' ' ')
-          if [[ -n "$EXISTING_KO_PR" ]]; then
-              echo "existing_pr_ko=true" >> $GITHUB_ENV
-              echo "existing_pr_ko_ref=$EXISTING_KO_PR" >> $GITHUB_ENV
+            "https://api.github.com/repos/${{ github.repository }}/pulls?state=open")
+          REF=$(echo "$RESPONSE" | jq -r '.[] | select(.head.ref | startswith("update-master-ko-")) | .head.ref' | head -n1)
+          if [[ -n "$REF" && "$REF" != "null" ]]; then
+            echo "existing_ko_pr=true" >> $GITHUB_ENV
+            echo "existing_ko_ref=$REF" >> $GITHUB_ENV
           else
-              echo "existing_pr_ko=false" >> $GITHUB_ENV
+            echo "existing_ko_pr=false" >> $GITHUB_ENV
           fi
-          echo "Existing PRs for master-ko update: $EXISTING_KO_PR"
-        shell: bash
+          echo "Existing master-ko PR branch: $REF"
 
       - name: Prepare master-ko Update
         run: |
           set -euo pipefail
-          # 최신 master 브랜치 체크아웃
-          git checkout master
-          # 원격의 master-ko 브랜치가 있으면 가져오고, 없으면 새로 생성
           git fetch origin master-ko || true
           git checkout -B master-ko origin/master-ko || git checkout -B master-ko
 
-          # 1) master-ko 패키지 백업
           cp package.json /tmp/pkg_old.json || true
-
-          # 2) upstream/master → master-ko (src, .github 제외) 복사 
           git checkout upstream/master -- . ":(exclude)src" ":(exclude).github"
 
-          # 3) package.json 깊이 병합
           node <<'NODE'
           const fs = require('fs');
           const oldPkg = fs.existsSync('/tmp/pkg_old.json') ? JSON.parse(fs.readFileSync('/tmp/pkg_old.json','utf8')) : {};
           const newPkg = JSON.parse(fs.readFileSync('package.json','utf8'));
-          
-          // 의존성 스마트 병합: upstream과 master-ko 둘 다에 있으면 upstream 버전, master-ko에만 있으면 유지
           ['dependencies','devDependencies','peerDependencies'].forEach(k=>{
-            const upstreamDeps = newPkg[k] || {};
-            const localDeps = oldPkg[k] || {};
-            const merged = {...upstreamDeps}; // upstream을 기본으로 시작
-            
-            // master-ko에만 있는 패키지들 추가
-            for(const pkg in localDeps) {
-              if(!(pkg in upstreamDeps)) {
-                merged[pkg] = localDeps[pkg];
-              }
-            }
-            newPkg[k] = merged;
+            const upstreamDeps=newPkg[k]||{}, localDeps=oldPkg[k]||{}, merged={...upstreamDeps};
+            for(const pkg in localDeps){ if(!(pkg in upstreamDeps)) merged[pkg]=localDeps[pkg]; }
+            newPkg[k]=merged;
           });
-          
-          // scripts는 기존 방식으로 병합 (중복되지 않는 것만 추가)
-          const merge = (a,b)=>{for(const k in b){if(b[k]&&typeof b[k]==='object'&&!Array.isArray(b[k]))a[k]=merge(a[k]||{},b[k]);else if(!(k in a))a[k]=b[k];}return a;}
-          if(oldPkg.scripts) {
-            newPkg.scripts = merge(newPkg.scripts||{}, oldPkg.scripts);
-          }
-          
+          const merge=(a,b)=>{for(const k in b){if(b[k]&&typeof b[k]==='object'&&!Array.isArray(b[k]))a[k]=merge(a[k]||{},b[k]);else if(!(k in a))a[k]=b[k];}return a;}
+          if(oldPkg.scripts){newPkg.scripts=merge(newPkg.scripts||{},oldPkg.scripts);}
           fs.writeFileSync('package.json',JSON.stringify(newPkg,null,2)+'\n');
           NODE
 
-          # 4) 로컬 전용 파일 복원 (존재할 때만)
           for f in .yarnrc.yml README.md; do
             git ls-files --error-unmatch "$f" >/dev/null 2>&1 && git checkout master-ko -- "$f" || true
           done
 
-          # 5) pnpm lockfile 클린 재생성
-          if command -v pnpm &> /dev/null; then
-            # 기존 lockfile 제거하고 클린 설치
-            rm -f pnpm-lock.yaml
-            pnpm install --frozen-lockfile=false
-            git add pnpm-lock.yaml
+          rm -f pnpm-lock.yaml
+          pnpm install --frozen-lockfile=false || true
+          git add -A
+          if git diff --cached --quiet; then
+            echo "master_ko_changed=false" >> $GITHUB_ENV
+          else
+            git commit -m "Update master-ko (deep-merge package.json, keep local files)"
+            echo "master_ko_changed=true" >> $GITHUB_ENV
           fi
 
-          git add .
-          git commit -m "Update master-ko (deep-merge package.json, keep local files including README.md)" || echo "No changes to commit"
-        shell: bash
-
-      - name: Compare Changes with Existing master-ko PRs
-        id: compare-changes-ko
-        if: env.existing_pr_ko == 'true'
+      - name: Push and Create/Update PR for master-ko
+        if: env.master_ko_changed == 'true'
         run: |
-          ALL_INCLUDED=true
-          EXISTING_BRANCH=""
-          for pr_ref in ${{ env.existing_pr_ko_ref }}
-          do
-            echo "Fetching branch: $pr_ref"
-            git fetch origin "$pr_ref:$pr_ref-branch"
-            echo "Comparing updated master-ko with existing PR branch (excluding src)"
-            if ! git diff --quiet master-ko "$pr_ref-branch" -- . ':(exclude)src'; then
-              ALL_INCLUDED=false
-              EXISTING_BRANCH=$pr_ref
-              break
-            fi
-          done
-
-          if [ "$ALL_INCLUDED" = true ]; then
-            echo "ko_diff=false" >> $GITHUB_ENV
+          if [[ "${{ env.existing_ko_pr }}" == "true" ]]; then
+            BRANCH="${{ env.existing_ko_ref }}"
+            echo "Updating existing master-ko PR branch: $BRANCH"
+            git push origin master-ko:"$BRANCH" --force
           else
-            echo "ko_diff=true" >> $GITHUB_ENV
-            if [ -n "$EXISTING_BRANCH" ]; then
-              PR_NUMBER=$(curl -s \
-                -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" \
-                -H "Accept: application/vnd.github.v3+json" \
-                "https://api.github.com/repos/${{ github.repository }}/pulls" \
-                | jq -r '.[] | select(.head.ref=="'$EXISTING_BRANCH'") | .number')
-              echo "Closing master-ko PR #$PR_NUMBER"
-              curl -X PATCH \
-                -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" \
-                -H "Accept: application/vnd.github.v3+json" \
-                https://api.github.com/repos/${{ github.repository }}/pulls/$PR_NUMBER \
-                -d '{"state":"closed"}'
-            fi
+            BRANCH="update-master-ko-$(date +%Y%m%d%H%M%S)"
+            git checkout -b "$BRANCH"
+            git push origin "$BRANCH"
+            curl -X POST \
+              -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" \
+              -H "Accept: application/vnd.github.v3+json" \
+              https://api.github.com/repos/${{ github.repository }}/pulls \
+              -d '{
+                "title": "Update master-ko (excluding src)",
+                "body": "This PR updates the master-ko branch with upstream changes except for the src directory.",
+                "head": "'"$BRANCH"'",
+                "base": "master-ko"
+              }'
           fi
-        shell: bash
-
-      - name: Update Existing master-ko PR Branch
-        if: env.existing_pr_ko == 'true' && env.ko_diff == 'false'
-        run: |
-          # 기존 PR 브랜치(첫번째 값)를 사용하여 업데이트
-          EXISTING_BRANCH=$(echo "${{ env.existing_pr_ko_ref }}" | awk '{print $1}')
-          echo "Pushing updated changes to existing master-ko branch: $EXISTING_BRANCH"
-          git push origin master-ko:"$EXISTING_BRANCH" --force
-        shell: bash
-
-      - name: Create New PR for master-ko Update
-        if: env.ko_diff == 'true' || env.existing_pr_ko == 'false'
-        run: |
-          BRANCH_NAME=update-master-ko-$(date +%Y%m%d%H%M%S)
-          git checkout -b $BRANCH_NAME
-          git push origin $BRANCH_NAME
-          curl -X POST \
-            -H "Authorization: token ${{ secrets.GITHUB_TOKEN }}" \
-            -H "Accept: application/vnd.github.v3+json" \
-            https://api.github.com/repos/${{ github.repository }}/pulls \
-            -d '{
-              "title": "Update master-ko (excluding src)",
-              "body": "This PR updates the master-ko branch with upstream changes except for the src directory.",
-              "head": "'"${BRANCH_NAME}"'",
-              "base": "master-ko"
-            }'
-        shell: bash
\ No newline at end of file