diff --git a/app/build.gradle b/app/build.gradle
index 4909d44..750e517 100644
--- a/app/build.gradle
+++ b/app/build.gradle
@@ -32,6 +32,22 @@
 
 dependencies {
 
+    androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
+
+
+    // 各 2021/11/23 時点の最新版
+    // Retrofit
+    implementation "com.squareup.retrofit2:retrofit:2.9.0"
+    implementation "com.squareup.retrofit2:converter-moshi:2.9.0"
+
+    implementation 'com.squareup.retrofit2:converter-jackson:2.5.0'
+    implementation 'com.squareup.retrofit2:converter-scalars:2.1.0'
+
+
+    // Moshi
+    implementation "com.squareup.moshi:moshi:1.12.0"
+    implementation "com.squareup.moshi:moshi-kotlin:1.12.0"
+
     implementation 'androidx.appcompat:appcompat:1.3.1'
     implementation 'com.google.android.material:material:1.4.0'
     implementation 'androidx.constraintlayout:constraintlayout:2.1.1'
@@ -43,16 +59,12 @@
     implementation 'androidx.lifecycle:lifecycle-extensions:2.2.0'
     implementation 'androidx.swiperefreshlayout:swiperefreshlayout:1.1.0'
     implementation 'androidx.legacy:legacy-support-v4:1.0.0'
-
     testImplementation 'junit:junit:4.+'
     androidTestImplementation 'androidx.test.ext:junit:1.1.3'
     androidTestImplementation 'androidx.test.espresso:espresso-core:3.4.0'
-
-    implementation "com.squareup.retrofit2:retrofit:2.5.0"
-    implementation 'com.squareup.retrofit2:converter-jackson:2.5.0'
-    implementation 'com.squareup.retrofit2:converter-scalars:2.1.0'
     implementation 'com.github.bumptech.glide:glide:4.10.0'
     annotationProcessor 'com.github.bumptech.glide:compiler:4.10.0'
     implementation 'com.google.android.material:material:1.1.0-alpha08'
     implementation 'androidx.viewpager2:viewpager2:1.0.0-beta02'
+
 }
\ No newline at end of file
diff --git a/app/src/main/java/org/ntlab/irisclient/models/Room.java b/app/src/main/java/org/ntlab/irisclient/models/Room.java
new file mode 100644
index 0000000..929b75b
--- /dev/null
+++ b/app/src/main/java/org/ntlab/irisclient/models/Room.java
@@ -0,0 +1,4 @@
+package org.ntlab.irisclient.models;
+
+public class Room {
+}
diff --git a/app/src/main/java/org/ntlab/irisclient/viewmodels/RoomViewModel.java b/app/src/main/java/org/ntlab/irisclient/viewmodels/RoomViewModel.java
new file mode 100644
index 0000000..5fd027f
--- /dev/null
+++ b/app/src/main/java/org/ntlab/irisclient/viewmodels/RoomViewModel.java
@@ -0,0 +1,37 @@
+package org.ntlab.irisclient.viewmodels;
+
+import org.ntlab.irisclient.models.Room;
+
+import java.net.URI;
+
+import androidx.lifecycle.LiveData;
+import androidx.lifecycle.MutableLiveData;
+import androidx.lifecycle.ViewModel;
+
+import retrofit2.Call;
+import retrofit2.Callback;
+import retrofit2.Response;
+import retrofit2.Retrofit;
+import retrofit2.converter.moshi.MoshiConverterFactory;
+import retrofit2.converter.jackson.JacksonConverterFactory;
+
+public class RoomViewModel extends ViewModel {
+
+    private MutableLiveData<Room> roomMutableLiveData;
+    private Retrofit retrofit;
+
+    //------------------------------------------------
+    public RoomViewModel() {
+        this.roomMutableLiveData = new MutableLiveData<>();
+        this.retrofit = new Retrofit.Builder()
+                .baseUrl("http://nitta-lab-www.is.konan-u.ac.jp/iris/")
+                .addConverterFactory(JacksonConverterFactory.create())
+                .build();
+    }
+
+    //-----------------------------------------------------------------
+    // getter
+    public LiveData<Room> getLiveData() {
+        return this.roomMutableLiveData;
+    }
+}