diff --git a/data/src/main/java/one/nem/lacerta/source/pref/impl/CommonImpl.java b/data/src/main/java/one/nem/lacerta/source/pref/impl/CommonImpl.java
index c8aa14e8..f9791c76 100644
--- a/data/src/main/java/one/nem/lacerta/source/pref/impl/CommonImpl.java
+++ b/data/src/main/java/one/nem/lacerta/source/pref/impl/CommonImpl.java
@@ -1,4 +1,55 @@
 package one.nem.lacerta.source.pref.impl;
 
+import android.content.Context;
+import android.content.SharedPreferences;
+
+import androidx.appcompat.app.AppCompatActivity;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import javax.inject.Inject;
+
 public class CommonImpl {
+
+    private final AppCompatActivity activity;
+
+    @Inject
+    public CommonImpl(AppCompatActivity activity) {
+        this.activity = activity;
+    }
+
+    public String getStringValue(String key) {
+        SharedPreferences pref = activity.getSharedPreferences("common", Context.MODE_PRIVATE);
+        return pref.getString(key, "");
+    }
+
+    public void setStringValue(String key, String value) {
+        SharedPreferences pref = activity.getSharedPreferences("common", Context.MODE_PRIVATE);
+        SharedPreferences.Editor editor = pref.edit();
+        editor.putString(key, value);
+        editor.apply();
+    }
+
+    public boolean isExist(String key) {
+        SharedPreferences pref = activity.getSharedPreferences("common", Context.MODE_PRIVATE);
+        return pref.contains(key);
+    }
+
+    public void remove(String key) {
+        SharedPreferences pref = activity.getSharedPreferences("common", Context.MODE_PRIVATE);
+        SharedPreferences.Editor editor = pref.edit();
+        editor.remove(key);
+        editor.apply();
+    }
+
+    public ArrayList<String> getExistKeys() {
+        SharedPreferences pref = activity.getSharedPreferences("common", Context.MODE_PRIVATE);
+        // キーだけをArrayListに切り出す
+        return new ArrayList<>(pref.getAll().keySet());
+    }
+
+
+
 }
diff --git a/data/src/main/java/one/nem/lacerta/source/pref/repository/Common.java b/data/src/main/java/one/nem/lacerta/source/pref/repository/Common.java
index 3fb0f187..dec372d0 100644
--- a/data/src/main/java/one/nem/lacerta/source/pref/repository/Common.java
+++ b/data/src/main/java/one/nem/lacerta/source/pref/repository/Common.java
@@ -1,5 +1,6 @@
 package one.nem.lacerta.source.pref.repository;
 
+import java.util.ArrayList;
 import java.util.List;
 
 public interface Common {
@@ -13,5 +14,5 @@ public interface Common {
 
     void remove(String key);
 
-    List<String> getExistKeys();
+    ArrayList<String> getExistKeys();
 }