diff --git a/src/sh/tuk/module/Common_Functions.bas b/src/sh/tuk/module/Common_Functions.bas
index 2f7616e..9a94659 100644
--- a/src/sh/tuk/module/Common_Functions.bas
+++ b/src/sh/tuk/module/Common_Functions.bas
@@ -368,12 +368,12 @@ Function CheckHeaderEdit(ByVal ws As Worksheet, ByVal Target As Range) As Boolea
     Dim sheetConf As Object: Set sheetConf = sheetConfDict(ws.CodeName)
     Dim filterRow As Long: filterRow = sheetConf("FilterRow")
 
-    ' Check header row (headerRow) cannot be edited
+    ' Check rows 1 to filterRow cannot be edited
     Dim r As Long
     For r = Target.Row To Target.Row + Target.Rows.Count - 1
-        If r = 1 Or r = filterRow Then
+        If r >= 1 And r <= filterRow Then
             Application.EnableEvents = False
-            MsgBox "Header or type definition row cannot be edited.", vbExclamation
+            MsgBox "Cannot edit rows 1 to " & filterRow & ".", vbExclamation
             Application.Undo
             Application.EnableEvents = True
 
diff --git a/src/sh/tuk/sheet/C1.cls b/src/sh/tuk/sheet/C1.cls
index 9e01982..593f94b 100644
--- a/src/sh/tuk/sheet/C1.cls
+++ b/src/sh/tuk/sheet/C1.cls
@@ -232,6 +232,18 @@ Finally:
     Application.EnableEvents = True ' 
 End Sub
 
+' Prevent insert/delete row in header area
+Private Sub Worksheet_BeforeRightClick(ByVal Target As Range, Cancel As Boolean)
+    Dim sheetConfDict As Object: Set sheetConfDict = GetSheetConfig()
+    Dim sheetConf As Object: Set sheetConf = sheetConfDict(Me.CodeName)
+    Dim filterRow As Long: filterRow = sheetConf("FilterRow")
+
+    If Target.Row < filterRow + 1 Then
+        Cancel = True
+        MsgBox "Cannot insert or delete row in header area.", vbExclamation
+    End If
+End Sub
+
 Private Sub RebuildDropdownsForTarget(ByVal Target As Range)
     If Target Is Nothing Then Exit Sub
     
diff --git a/src/sh/tuk/sheet/M1.cls b/src/sh/tuk/sheet/M1.cls
index 8a8dcd9..7214296 100644
--- a/src/sh/tuk/sheet/M1.cls
+++ b/src/sh/tuk/sheet/M1.cls
@@ -10,7 +10,10 @@
 Private Sub Worksheet_Change(ByVal Target As Range)
     Dim HasHeaderEdit As Boolean: HasHeaderEdit = CheckHeaderEdit(Me, Target)
     If HasHeaderEdit = True Then Exit Sub
-
+    
+    ' Multi-cell selection not processed
+    If Target.Count > 1 Then Exit Sub
+    
     ' === Column C changes: Create L column dropdown ===
     If Target.Column = 3 And Target.Row >= 7 Then
         Dim cell As Range
@@ -46,6 +49,18 @@ Private Sub Worksheet_Change(ByVal Target As Range)
     End If
 End Sub
 
+' Prevent insert/delete row in header area
+Private Sub Worksheet_BeforeRightClick(ByVal Target As Range, Cancel As Boolean)
+    Dim sheetConfDict As Object: Set sheetConfDict = GetSheetConfig()
+    Dim sheetConf As Object: Set sheetConf = sheetConfDict(Me.CodeName)
+    Dim filterRow As Long: filterRow = sheetConf("FilterRow")
+
+    If Target.Row < filterRow + 1 Then
+        Cancel = True
+        MsgBox "Cannot insert or delete row in header area.", vbExclamation
+    End If
+End Sub
+
 Private Sub Validate(ws As Worksheet, ByVal rowNum As Long, ByVal lastDataRow As Long)
     On Error GoTo ErrHandler
     
diff --git a/src/sh/tuk/sheet/M2.cls b/src/sh/tuk/sheet/M2.cls
index 34fd686..1a0e85c 100644
--- a/src/sh/tuk/sheet/M2.cls
+++ b/src/sh/tuk/sheet/M2.cls
@@ -94,6 +94,18 @@ Finally:
     Application.EnableEvents = True ' 
 End Sub
 
+' Prevent insert/delete row in header area
+Private Sub Worksheet_BeforeRightClick(ByVal Target As Range, Cancel As Boolean)
+    Dim sheetConfDict As Object: Set sheetConfDict = GetSheetConfig()
+    Dim sheetConf As Object: Set sheetConf = sheetConfDict(Me.CodeName)
+    Dim filterRow As Long: filterRow = sheetConf("FilterRow")
+
+    If Target.Row < filterRow + 1 Then
+        Cancel = True
+        MsgBox "Cannot insert or delete row in header area.", vbExclamation
+    End If
+End Sub
+
 Public Sub Validate(ws As Worksheet, ByVal rowNum As Long, ByVal lastDataRow As Long)
     On Error GoTo ErrHandler
     
diff --git a/src/sh/tuk/sheet/O1.cls b/src/sh/tuk/sheet/O1.cls
index 0276b40..c233aa9 100644
--- a/src/sh/tuk/sheet/O1.cls
+++ b/src/sh/tuk/sheet/O1.cls
@@ -13,6 +13,18 @@ Private Sub Worksheet_Change(ByVal Target As Range)
     If HasHeaderEdit = True Then Exit Sub
 End Sub
 
+' Prevent insert/delete row in header area
+Private Sub Worksheet_BeforeRightClick(ByVal Target As Range, Cancel As Boolean)
+    Dim sheetConfDict As Object: Set sheetConfDict = GetSheetConfig()
+    Dim sheetConf As Object: Set sheetConf = sheetConfDict(Me.CodeName)
+    Dim filterRow As Long: filterRow = sheetConf("FilterRow")
+
+    If Target.Row < filterRow + 1 Then
+        Cancel = True
+        MsgBox "Cannot insert or delete row in header area.", vbExclamation
+    End If
+End Sub
+
 Public Sub Validate(ws As Worksheet, ByVal rowNum As Long, ByVal lastDataRow As Long)
     On Error GoTo ErrHandler
     
diff --git a/src/sh/tuk/sheet/O2.cls b/src/sh/tuk/sheet/O2.cls
index 8cfc547..106d756 100644
--- a/src/sh/tuk/sheet/O2.cls
+++ b/src/sh/tuk/sheet/O2.cls
@@ -14,6 +14,18 @@ Private Sub Worksheet_Change(ByVal Target As Range)
 
 End Sub
 
+' Prevent insert/delete row in header area
+Private Sub Worksheet_BeforeRightClick(ByVal Target As Range, Cancel As Boolean)
+    Dim sheetConfDict As Object: Set sheetConfDict = GetSheetConfig()
+    Dim sheetConf As Object: Set sheetConf = sheetConfDict(Me.CodeName)
+    Dim filterRow As Long: filterRow = sheetConf("FilterRow")
+
+    If Target.Row < filterRow + 1 Then
+        Cancel = True
+        MsgBox "Cannot insert or delete row in header area.", vbExclamation
+    End If
+End Sub
+
 Public Sub Validate(ws As Worksheet, ByVal rowNum As Long, ByVal lastDataRow As Long)
     On Error GoTo ErrHandler
     
diff --git a/src/sh/tuk/sheet/T1.cls b/src/sh/tuk/sheet/T1.cls
index 64891cd..2a96df4 100644
--- a/src/sh/tuk/sheet/T1.cls
+++ b/src/sh/tuk/sheet/T1.cls
@@ -15,6 +15,18 @@ Private Sub Worksheet_Change(ByVal Target As Range)
 
 End Sub
 
+' Prevent insert/delete row in header area
+Private Sub Worksheet_BeforeRightClick(ByVal Target As Range, Cancel As Boolean)
+    Dim sheetConfDict As Object: Set sheetConfDict = GetSheetConfig()
+    Dim sheetConf As Object: Set sheetConf = sheetConfDict(Me.CodeName)
+    Dim filterRow As Long: filterRow = sheetConf("FilterRow")
+
+    If Target.Row < filterRow + 1 Then
+        Cancel = True
+        MsgBox "Cannot insert or delete row in header area.", vbExclamation
+    End If
+End Sub
+
 ' 
 Public Sub Validate(ws As Worksheet, ByVal rowNum As Long, ByVal lastDataRow As Long)
     On Error GoTo ErrHandler
diff --git a/src/sh/tuk/sheet/T2.cls b/src/sh/tuk/sheet/T2.cls
index af22fb2..c429e0b 100644
--- a/src/sh/tuk/sheet/T2.cls
+++ b/src/sh/tuk/sheet/T2.cls
@@ -15,6 +15,18 @@ Private Sub Worksheet_Change(ByVal Target As Range)
 
 End Sub
 
+' Prevent insert/delete row in header area
+Private Sub Worksheet_BeforeRightClick(ByVal Target As Range, Cancel As Boolean)
+    Dim sheetConfDict As Object: Set sheetConfDict = GetSheetConfig()
+    Dim sheetConf As Object: Set sheetConf = sheetConfDict(Me.CodeName)
+    Dim filterRow As Long: filterRow = sheetConf("FilterRow")
+
+    If Target.Row < filterRow + 1 Then
+        Cancel = True
+        MsgBox "Cannot insert or delete row in header area.", vbExclamation
+    End If
+End Sub
+
 ' 
 Public Sub Validate(ws As Worksheet, ByVal rowNum As Long, ByVal lastDataRow As Long)
     On Error GoTo ErrHandler
diff --git a/src/sh/tuk/sheet/T3.cls b/src/sh/tuk/sheet/T3.cls
index 153a46a..acc07dd 100644
--- a/src/sh/tuk/sheet/T3.cls
+++ b/src/sh/tuk/sheet/T3.cls
@@ -15,6 +15,18 @@ Private Sub Worksheet_Change(ByVal Target As Range)
 
 End Sub
 
+' Prevent insert/delete row in header area
+Private Sub Worksheet_BeforeRightClick(ByVal Target As Range, Cancel As Boolean)
+    Dim sheetConfDict As Object: Set sheetConfDict = GetSheetConfig()
+    Dim sheetConf As Object: Set sheetConf = sheetConfDict(Me.CodeName)
+    Dim filterRow As Long: filterRow = sheetConf("FilterRow")
+
+    If Target.Row < filterRow + 1 Then
+        Cancel = True
+        MsgBox "Cannot insert or delete row in header area.", vbExclamation
+    End If
+End Sub
+
 ' 
 Public Sub Validate(ws As Worksheet, ByVal rowNum As Long, ByVal lastDataRow As Long)
     On Error GoTo ErrHandler
diff --git a/src/sh/tuk/sheet/Z1.cls b/src/sh/tuk/sheet/Z1.cls
index 3dd78ff..4ac35c2 100644
--- a/src/sh/tuk/sheet/Z1.cls
+++ b/src/sh/tuk/sheet/Z1.cls
@@ -15,6 +15,18 @@ Private Sub Worksheet_Change(ByVal Target As Range)
 
 End Sub
 
+' Prevent insert/delete row in header area
+Private Sub Worksheet_BeforeRightClick(ByVal Target As Range, Cancel As Boolean)
+    Dim sheetConfDict As Object: Set sheetConfDict = GetSheetConfig()
+    Dim sheetConf As Object: Set sheetConf = sheetConfDict(Me.CodeName)
+    Dim filterRow As Long: filterRow = sheetConf("FilterRow")
+
+    If Target.Row < filterRow + 1 Then
+        Cancel = True
+        MsgBox "Cannot insert or delete row in header area.", vbExclamation
+    End If
+End Sub
+
 '
 Public Sub Validate(ws As Worksheet, ByVal rowNum As Long, ByVal lastDataRow As Long)
     On Error GoTo ErrHandler
diff --git a/src/sh/tuk/sheet/Z2.cls b/src/sh/tuk/sheet/Z2.cls
index 241c410..e7a6b77 100644
--- a/src/sh/tuk/sheet/Z2.cls
+++ b/src/sh/tuk/sheet/Z2.cls
@@ -15,6 +15,18 @@ Private Sub Worksheet_Change(ByVal Target As Range)
 
 End Sub
 
+' Prevent insert/delete row in header area
+Private Sub Worksheet_BeforeRightClick(ByVal Target As Range, Cancel As Boolean)
+    Dim sheetConfDict As Object: Set sheetConfDict = GetSheetConfig()
+    Dim sheetConf As Object: Set sheetConf = sheetConfDict(Me.CodeName)
+    Dim filterRow As Long: filterRow = sheetConf("FilterRow")
+
+    If Target.Row < filterRow + 1 Then
+        Cancel = True
+        MsgBox "Cannot insert or delete row in header area.", vbExclamation
+    End If
+End Sub
+
 ' 
 Public Sub Validate(ws As Worksheet, ByVal rowNum As Long, ByVal lastDataRow As Long)
     On Error GoTo ErrHandler
diff --git a/src/sh/tuk/sheet/Z3.cls b/src/sh/tuk/sheet/Z3.cls
index 39f2f45..032d5ce 100644
--- a/src/sh/tuk/sheet/Z3.cls
+++ b/src/sh/tuk/sheet/Z3.cls
@@ -15,6 +15,18 @@ Private Sub Worksheet_Change(ByVal Target As Range)
 
 End Sub
 
+' Prevent insert/delete row in header area
+Private Sub Worksheet_BeforeRightClick(ByVal Target As Range, Cancel As Boolean)
+    Dim sheetConfDict As Object: Set sheetConfDict = GetSheetConfig()
+    Dim sheetConf As Object: Set sheetConf = sheetConfDict(Me.CodeName)
+    Dim filterRow As Long: filterRow = sheetConf("FilterRow")
+
+    If Target.Row < filterRow + 1 Then
+        Cancel = True
+        MsgBox "Cannot insert or delete row in header area.", vbExclamation
+    End If
+End Sub
+
 ' 
 Public Sub Validate(ws As Worksheet, ByVal rowNum As Long, ByVal lastDataRow As Long)
     On Error GoTo ErrHandler
diff --git a/src/sh/tuk/sheet/Z4.cls b/src/sh/tuk/sheet/Z4.cls
index 00b3d77..71e89f0 100644
--- a/src/sh/tuk/sheet/Z4.cls
+++ b/src/sh/tuk/sheet/Z4.cls
@@ -15,6 +15,18 @@ Private Sub Worksheet_Change(ByVal Target As Range)
 
 End Sub
 
+' Prevent insert/delete row in header area
+Private Sub Worksheet_BeforeRightClick(ByVal Target As Range, Cancel As Boolean)
+    Dim sheetConfDict As Object: Set sheetConfDict = GetSheetConfig()
+    Dim sheetConf As Object: Set sheetConf = sheetConfDict(Me.CodeName)
+    Dim filterRow As Long: filterRow = sheetConf("FilterRow")
+
+    If Target.Row < filterRow + 1 Then
+        Cancel = True
+        MsgBox "Cannot insert or delete row in header area.", vbExclamation
+    End If
+End Sub
+
 ' 
 Public Sub Validate(ws As Worksheet, ByVal rowNum As Long, ByVal lastDataRow As Long)
     On Error GoTo ErrHandler
diff --git a/通勤手当テンプレート20260515.xlsm b/通勤手当テンプレート20260515.xlsm
index 26f5489..5282ef6 100644
Binary files a/通勤手当テンプレート20260515.xlsm and b/通勤手当テンプレート20260515.xlsm differ