diff --git a/app/build.gradle b/app/build.gradle
index 0bd8e5a..5f81937 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -57,6 +57,7 @@
     compile "android.arch.lifecycle:extensions:1.0.0"
     annotationProcessor "android.arch.lifecycle:compiler:1.0.0"
 
+    // Rx
     implementation "io.reactivex.rxjava2:rxjava:$rx_java_version"
     implementation "io.reactivex.rxjava2:rxandroid:$rx_android_version"
 
diff --git a/app/src/main/java/com/example/sprout/refactor/model/RegistrationModel.java b/app/src/main/java/com/example/sprout/refactor/model/RegistrationModel.java
index 5ecc0e9..f3fc860 100644
--- a/app/src/main/java/com/example/sprout/refactor/model/RegistrationModel.java
+++ b/app/src/main/java/com/example/sprout/refactor/model/RegistrationModel.java
@@ -3,47 +3,55 @@
 import com.example.sprout.refactor.model.entity.Account;
 import com.example.sprout.refactor.repository.RegistrationRepository;
 
+import io.reactivex.Observable;
 import io.reactivex.schedulers.Schedulers;
+import io.reactivex.subjects.BehaviorSubject;
+import io.reactivex.subjects.PublishSubject;
 
 /**
  * Accountを管理するクラス
  * Created by matsumoto_k on 2017/12/14.
  */
 
-public class RegistrationModel extends BaseModel<Account, Account> {
+public class RegistrationModel {
 
+    private BehaviorSubject<Account> accountSubject = BehaviorSubject.create();
+    private PublishSubject<Throwable> errorSubject = PublishSubject.create();
     private RegistrationRepository registrationRepository = null;
 
     public RegistrationModel(RegistrationRepository registrationRepository) {
         this.registrationRepository = registrationRepository;
     }
 
-    @Override
-    public void create(Account account) {
-        registrationRepository.registration(account.getUserName())
+    public void create(String userName) {
+        registrationRepository.registration(userName)
                 .subscribeOn(Schedulers.computation())
                 .subscribe(
-                        response -> entitySubject.onNext(response),
+                        response -> accountSubject.onNext(response),
                         error -> errorSubject.onNext(error)
                 );
     }
 
-    @Override
-    public void read(Account account) {
-        registrationRepository.getAccount(account.getUserID())
+    public void get(int userId) {
+        registrationRepository.getAccount(userId)
                 .subscribeOn(Schedulers.computation())
                 .subscribe(
-                        response -> entitySubject.onNext(account),
-                        error -> errorSubject.onNext(error)
+                        account -> accountSubject.onNext(account),
+                        error -> {
+                            if (accountSubject.getValue() != null) {
+                                accountSubject.onNext(accountSubject.getValue());
+                            }
+                            errorSubject.onNext(error);
+
+                        }
                 );
     }
 
-    @Override
-    public void update(Account account) {
+    public Observable<Account> getAccountObservable() {
+        return accountSubject;
     }
 
-    @Override
-    public void delete(Account account) {
-
+    public Observable<Throwable> getErrorObservable() {
+        return errorSubject;
     }
 }
diff --git a/app/src/main/java/com/example/sprout/refactor/viewmodel/RegistrationViewModel.java b/app/src/main/java/com/example/sprout/refactor/viewmodel/RegistrationViewModel.java
index 1a367c0..2d94e8f 100644
--- a/app/src/main/java/com/example/sprout/refactor/viewmodel/RegistrationViewModel.java
+++ b/app/src/main/java/com/example/sprout/refactor/viewmodel/RegistrationViewModel.java
@@ -11,7 +11,6 @@
 import com.example.sprout.refactor.messengers.ToastMessenger;
 import com.example.sprout.refactor.model.ModelLocator;
 import com.example.sprout.refactor.model.RegistrationModel;
-import com.example.sprout.refactor.model.entity.Account;
 import com.example.sprout.refactor.util.PreferenceUtil;
 
 import io.reactivex.Observable;
@@ -44,7 +43,7 @@
     public void onResume() {
         super.onResume();
         subscriptions.add(
-                registrationModel.getEntityObservable()
+                registrationModel.getAccountObservable()
                         .observeOn(AndroidSchedulers.mainThread())
                         .subscribe(account -> {
                                     preferenceUtil.saveInt(PreferenceUtil.Key.USER_ID, account.getUserID());
@@ -80,9 +79,7 @@
             toastMessanger.showToast(new ToastMessage(Sprout.get().getResources().getString(R.string.empty_name), ToastMessage.Length.SHORT));
             return;
         }
-        Account params = new Account();
-        params.setUserName(userName);
-        registrationModel.create(params);
+        registrationModel.create(userName);
 
     }