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..ef65af5 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
@@ -1,15 +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 +12,7 @@
  *
  * @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 +21,14 @@
     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;
-        }
-    }
-
-    @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 onResume() {
+        super.onResume();
+        addUiObserver(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 6ee33a0..3a34899 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
@@ -29,8 +29,21 @@
                 .subscribe(
                         roomResponse -> {
                             if (roomResponse.canEnter()) {
-                                preferenceUtil.saveInt(PreferenceUtil.Key.ROOM_ID, roomResponse.getRoom().getRoomId());
-                                preferenceUtil.saveInt(PreferenceUtil.Key.MEMBER_ID, roomResponse.getMemberId());
+                                roomResopnseSubject.onNext(roomResponse);
+                            }
+                        },
+                        error -> {
+                            errorSubject.onNext(new Error(error));
+                        }
+                );
+    }
+
+    public void enterRoomWithKey(int roomId, int userId, String key) {
+        roomRepository.enterRoomWithKey(roomId, userId, key)
+                .subscribeOn(Schedulers.computation())
+                .subscribe(
+                        roomResponse -> {
+                            if (roomResponse.canEnter()) {
                                 roomResopnseSubject.onNext(roomResponse);
                             }
                         },
@@ -54,7 +67,13 @@
     }
 
     public Observable<RoomResponse> getRoomResopnseObservable() {
-        return roomResopnseSubject.hide();
+        return roomResopnseSubject
+                .hide()
+                .doOnNext(roomResponse -> {
+                            preferenceUtil.saveInt(PreferenceUtil.Key.ROOM_ID, roomResponse.getRoom().getRoomId());
+                            preferenceUtil.saveInt(PreferenceUtil.Key.MEMBER_ID, roomResponse.getMemberId());
+                        }
+                );
     }
 
     public Observable<Error> getErrorObservable() {
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..e9887ff 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 +2,11 @@
 
 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.entity.RoomResponse;
-import com.example.sprout.refactor.notification.Observer;
-import com.example.sprout.refactor.repository.RoomRepository;
+import com.example.sprout.refactor.model.RoomResponseModel;
 import com.example.sprout.refactor.util.PreferenceUtil;
 
 /**
@@ -17,59 +16,54 @@
  */
 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;
-
-        observer = new Observer<RoomResponse>() {
-            @Override
-            public void notify(RoomResponse roomResponse) {
-                if (roomResponse.canEnter()) {
-                    ModelLocator.setModel(ModelLocator.Tag.RoomResponse, roomResponse);
-                    viewContract.startActivity(ActivityEvent.ROOM_MAIN);
-                } else {
-                    viewContract.showShortToast("入室に失敗しました");
-                }
-            }
-
-            @Override
-            public void error(Throwable throwable) {
-                viewContract.showShortToast("入室に失敗しました");
-            }
-        };
+    public RoomInputKeyViewModel() {
     }
 
     @Override
     public void onResume() {
         super.onResume();
-        roomRepository.getRoomResponseObservable().addObserver(observer);
+        subscriptions.add(
+                roomResponseModel.getRoomResopnseObservable()
+                        .subscribe(
+                                roomResponse -> {
+                                    if (roomResponse.canEnter()) {
+                                        navigationMessenger.navigateTo(new NavigationMessage(NavigationMessage.Type.Start, RoomMainActivity.class));
+                                        navigationMessenger.navigateTo(new NavigationMessage(NavigationMessage.Type.Finsih));
+                                    }
+                                }
+                        )
+        );
+        subscriptions.add(
+                roomResponseModel.getErrorObservable()
+                        .subscribe(error -> {
+                            switch (error.type()) {
+                                case CONFLICT:
+                                    toastMessanger.showToast(new ToastMessage("入室に失敗しました", ToastMessage.Length.SHORT));
+                                    break;
+                                case NetworkError:
+                                    toastMessanger.showToast(new ToastMessage("電波の良い場所に移動してもう一度試して下さい", ToastMessage.Length.SHORT));
+                            }
+                        })
+        );
     }
 
-    @Override
-    public void onPause() {
-        super.onPause();
-        roomRepository.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");
+    public void onClickEnter(String key) {
+        if (key.isEmpty()) {
+            toastMessanger.showToast(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
+                    key
             );
         }
     }
 
     public void onClickBack() {
-        viewContract.finishActivity();
+        navigationMessenger.navigateTo(new NavigationMessage(NavigationMessage.Type.Finsih));
     }
 
     public ObservableField<String> getPass() {