diff --git a/app/src/main/java/com/example/sprout/refactor/activity/RoomInputKeyActivity.java b/app/src/main/java/com/example/sprout/refactor/activity/RoomInputKeyActivity.java
index 115f5a1..58dfaa8 100644
--- a/app/src/main/java/com/example/sprout/refactor/activity/RoomInputKeyActivity.java
+++ b/app/src/main/java/com/example/sprout/refactor/activity/RoomInputKeyActivity.java
@@ -1,14 +1,10 @@
 package com.example.sprout.refactor.activity;
 
-import android.content.Intent;
 import android.databinding.DataBindingUtil;
 import android.os.Bundle;
-import android.support.v7.app.AppCompatActivity;
-import android.widget.Toast;
 
 import com.example.sprout.R;
 import com.example.sprout.databinding.RfActivityRoomInputKeyBinding;
-import com.example.sprout.refactor.common.ActivityEvent;
 import com.example.sprout.refactor.contract.ViewContract;
 import com.example.sprout.refactor.viewmodel.RoomInputKeyViewModel;
 
@@ -17,7 +13,7 @@
  *
  * @author matsumoto_k
  */
-public class RoomInputKeyActivity extends AppCompatActivity implements ViewContract {
+public class RoomInputKeyActivity extends BaseActivity {
 
     private RfActivityRoomInputKeyBinding binding = null;
     private RoomInputKeyViewModel roomInputKeyViewModel = null;
@@ -26,32 +22,20 @@
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         binding = DataBindingUtil.setContentView(this, R.layout.rf_activity_room_input_key);
-        roomInputKeyViewModel = new RoomInputKeyViewModel((ViewContract) this);
+        roomInputKeyViewModel = new RoomInputKeyViewModel();
         binding.setViewModel(roomInputKeyViewModel);
         getLifecycle().addObserver(roomInputKeyViewModel);
     }
 
     @Override
-    public void startActivity(ActivityEvent event) {
-        switch (event) {
-            case ROOM_MAIN:
-                startActivity(new Intent(RoomInputKeyActivity.this, RoomMainActivity.class));
-                break;
-        }
+    protected void onResume() {
+        super.onResume();
+        addUiObserver(roomInputKeyViewModel);
     }
 
     @Override
-    public void finishActivity() {
-        finish();
-    }
-
-    @Override
-    public void showShortToast(String message) {
-        Toast.makeText(this, message, Toast.LENGTH_SHORT).show();
-    }
-
-    @Override
-    public void showLongToast(String message) {
-        Toast.makeText(this, message, Toast.LENGTH_LONG).show();
+    protected void onPause() {
+        super.onPause();
+        removeUiObserver(roomInputKeyViewModel);
     }
 }
diff --git a/app/src/main/java/com/example/sprout/refactor/model/RoomResponseModel.java b/app/src/main/java/com/example/sprout/refactor/model/RoomResponseModel.java
index e2b6858..ccd4e9e 100644
--- a/app/src/main/java/com/example/sprout/refactor/model/RoomResponseModel.java
+++ b/app/src/main/java/com/example/sprout/refactor/model/RoomResponseModel.java
@@ -34,12 +34,16 @@
         this.roomRepository.getRoomResponseObservable().addObserver(roomResponseObserver);
     }
 
+    public void createRoom(int userId, String roomName, String key) {
+        roomRepository.createRoom(userId, roomName, key);
+    }
+
     public void enterRoom(int roomId, int userId) {
         roomRepository.enterRoom(roomId, userId);
     }
 
-    public void createRoom(int userId, String roomName, String key) {
-        roomRepository.createRoom(userId, roomName, key);
+    public void enterRoomWithKey(int roomId, int userId, String key) {
+        roomRepository.enterRoomWithKey(roomId, userId, key);
     }
 
     public Observable<RoomResponse> getRoomResponseObservable() {
diff --git a/app/src/main/java/com/example/sprout/refactor/viewmodel/RoomInputKeyViewModel.java b/app/src/main/java/com/example/sprout/refactor/viewmodel/RoomInputKeyViewModel.java
index 9bcc836..23755de 100644
--- a/app/src/main/java/com/example/sprout/refactor/viewmodel/RoomInputKeyViewModel.java
+++ b/app/src/main/java/com/example/sprout/refactor/viewmodel/RoomInputKeyViewModel.java
@@ -2,12 +2,13 @@
 
 import android.databinding.ObservableField;
 
-import com.example.sprout.refactor.common.ActivityEvent;
-import com.example.sprout.refactor.contract.ViewContract;
+import com.example.sprout.refactor.activity.RoomMainActivity;
+import com.example.sprout.refactor.messengers.NavigationMessage;
+import com.example.sprout.refactor.messengers.ToastMessage;
 import com.example.sprout.refactor.model.ModelLocator;
+import com.example.sprout.refactor.model.RoomResponseModel;
 import com.example.sprout.refactor.model.entity.RoomResponse;
 import com.example.sprout.refactor.notification.Observer;
-import com.example.sprout.refactor.repository.RoomRepository;
 import com.example.sprout.refactor.util.PreferenceUtil;
 
 /**
@@ -17,29 +18,24 @@
  */
 public class RoomInputKeyViewModel extends BaseViewModel {
 
-    private RoomRepository roomRepository = null;
-    private ViewContract viewContract = null;
+    private RoomResponseModel roomResponseModel = ModelLocator.get().getRoomResponseModel();
     private ObservableField<String> pass = new ObservableField<>("");
     private Observer<RoomResponse> observer = null;
 
-    public RoomInputKeyViewModel(ViewContract viewContract) {
-        this.roomRepository = ModelLocator.getModel(ModelLocator.Tag.ROOM_REPOSITORY, RoomRepository.class);
-        this.viewContract = viewContract;
-
+    public RoomInputKeyViewModel() {
         observer = new Observer<RoomResponse>() {
             @Override
             public void notify(RoomResponse roomResponse) {
                 if (roomResponse.canEnter()) {
-                    ModelLocator.setModel(ModelLocator.Tag.RoomResponse, roomResponse);
-                    viewContract.startActivity(ActivityEvent.ROOM_MAIN);
+                    navigationObservable.notifyObservers(new NavigationMessage(NavigationMessage.Type.Start, RoomMainActivity.class));
                 } else {
-                    viewContract.showShortToast("入室に失敗しました");
+                    toastObservable.notifyObservers(new ToastMessage("入室に失敗しました", ToastMessage.Length.SHORT));
                 }
             }
 
             @Override
             public void error(Throwable throwable) {
-                viewContract.showShortToast("入室に失敗しました");
+                toastObservable.notifyObservers(new ToastMessage("入室に失敗しました", ToastMessage.Length.SHORT));
             }
         };
     }
@@ -47,20 +43,20 @@
     @Override
     public void onResume() {
         super.onResume();
-        roomRepository.getRoomResponseObservable().addObserver(observer);
+        roomResponseModel.getRoomResponseObservable().addObserver(observer);
     }
 
     @Override
     public void onPause() {
         super.onPause();
-        roomRepository.getRoomResponseObservable().removeObserver(observer);
+        roomResponseModel.getRoomResponseObservable().removeObserver(observer);
     }
 
     public void onClickEnter(String pass) {
         if (pass.isEmpty()) {
-            viewContract.showShortToast("パスワードを入力して下さい");
+            toastObservable.notifyObservers(new ToastMessage("パスワードを入力して下さい", ToastMessage.Length.SHORT));
         } else {
-            roomRepository.enterRoomWithKey(
+            roomResponseModel.enterRoomWithKey(
                     PreferenceUtil.getInstance().getInt(PreferenceUtil.Key.ROOM_ID),
                     PreferenceUtil.getInstance().getInt(PreferenceUtil.Key.USER_ID),
                     pass
@@ -69,7 +65,7 @@
     }
 
     public void onClickBack() {
-        viewContract.finishActivity();
+        navigationObservable.notifyObservers(new NavigationMessage(NavigationMessage.Type.Finish));
     }
 
     public ObservableField<String> getPass() {