diff --git a/app/src/main/java/jp/juggler/subwaytooter/ActAppSettingChild.kt b/app/src/main/java/jp/juggler/subwaytooter/ActAppSettingChild.kt
index 0580c4c6..435c60da 100644
--- a/app/src/main/java/jp/juggler/subwaytooter/ActAppSettingChild.kt
+++ b/app/src/main/java/jp/juggler/subwaytooter/ActAppSettingChild.kt
@@ -704,9 +704,13 @@ class ActAppSettingChild : AppCompatActivity()
 	private fun loadUIFromData() {
 		load_busy = true
 		
-		for(si in booleanViewList) {
-			si.view.isChecked = si.info(pref)
-		}
+		pref.edit().also{ e->
+			for(si in booleanViewList) {
+				val curVal = si.info(pref)
+				si.view.isChecked = curVal
+				if( curVal == si.info.defVal) si.info.remove(e)
+			}
+		}.apply()
 		
 		spBackButtonAction?.setSelection(Pref.ipBackButtonAction(pref))
 		spRepliesCount?.setSelection(Pref.ipRepliesCount(pref))
@@ -834,7 +838,7 @@ class ActAppSettingChild : AppCompatActivity()
 		val e = pref.edit()
 		
 		for(si in booleanViewList) {
-			e.putBoolean(si.info.key, si.view.isChecked)
+			si.info.putOrRemove(e,si.view.isChecked)
 		}
 		
 		spDefaultAccount?.let {
diff --git a/app/src/main/java/jp/juggler/subwaytooter/Pref.kt b/app/src/main/java/jp/juggler/subwaytooter/Pref.kt
index cbda8c1a..5da4b183 100644
--- a/app/src/main/java/jp/juggler/subwaytooter/Pref.kt
+++ b/app/src/main/java/jp/juggler/subwaytooter/Pref.kt
@@ -40,7 +40,7 @@ fun SharedPreferences.Editor.remove(item : BasePref<*>) : SharedPreferences.Edit
 
 class BooleanPref(
 	key : String,
-	private val defVal : Boolean,
+	val defVal : Boolean,
 	val id : Int =0
 ) : BasePref<Boolean>(key) {
 	
@@ -51,6 +51,15 @@ class BooleanPref(
 	override fun put(editor : SharedPreferences.Editor, v : Boolean) {
 		editor.putBoolean(key, v)
 	}
+	
+	// put if value is not default, remove if value is same to default
+	fun putOrRemove(editor : SharedPreferences.Editor, v : Boolean) {
+		if( v != defVal) {
+			editor.putBoolean(key, v)
+		}else{
+			editor.remove(key)
+		}
+	}
 }
 
 class IntPref(key : String, val defVal : Int) : BasePref<Int>(key) {
@@ -460,7 +469,7 @@ object Pref {
 	
 	val bpShowBookmarkButton = BooleanPref(
 		"ShowBookmarkButton",
-		false,
+		true,
 		R.id.swShowBookmarkButton
 	)