diff --git a/app/src/main/java/keijumt/devandroid/api/PostalCodeApi.kt b/app/src/main/java/keijumt/devandroid/api/PostalCodeApi.kt
new file mode 100644
index 0000000..1a2a141
--- /dev/null
+++ b/app/src/main/java/keijumt/devandroid/api/PostalCodeApi.kt
@@ -0,0 +1,12 @@
+package keijumt.devandroid.api
+
+import io.reactivex.Single
+import keijumt.devandroid.api.response.PostalCode
+import retrofit2.http.GET
+import retrofit2.http.Query
+
+interface PostalCodeApi {
+
+    @GET("search")
+    fun getPostalCode(@Query("zipcode") zipcode: Int): Single<PostalCode>
+}
\ No newline at end of file
diff --git a/app/src/main/java/keijumt/devandroid/api/response/PostalCode.kt b/app/src/main/java/keijumt/devandroid/api/response/PostalCode.kt
new file mode 100644
index 0000000..285b12f
--- /dev/null
+++ b/app/src/main/java/keijumt/devandroid/api/response/PostalCode.kt
@@ -0,0 +1,7 @@
+package keijumt.devandroid.api.response
+
+data class PostalCode(
+        val status: Int,
+        val message: String,
+        val results: List<PostalCodeResult>?
+)
\ No newline at end of file
diff --git a/app/src/main/java/keijumt/devandroid/api/response/PostalCodeResult.kt b/app/src/main/java/keijumt/devandroid/api/response/PostalCodeResult.kt
new file mode 100644
index 0000000..9ffc2e2
--- /dev/null
+++ b/app/src/main/java/keijumt/devandroid/api/response/PostalCodeResult.kt
@@ -0,0 +1,12 @@
+package keijumt.devandroid.api.response
+
+class PostalCodeResult(
+        val address1: String,
+        val address2: String,
+        val address3: String,
+        val kana1: String,
+        val kana2: String,
+        val kana3: String,
+        val prefcode: String,
+        val zipcode: Int
+)
\ No newline at end of file
diff --git a/app/src/main/java/keijumt/devandroid/di/AppComponent.kt b/app/src/main/java/keijumt/devandroid/di/AppComponent.kt
index 7a16d2a..5812640 100644
--- a/app/src/main/java/keijumt/devandroid/di/AppComponent.kt
+++ b/app/src/main/java/keijumt/devandroid/di/AppComponent.kt
@@ -8,12 +8,14 @@
 import keijumt.devandroid.App
 import keijumt.devandroid.di.module.ActivityModule
 import keijumt.devandroid.di.module.AppModule
+import keijumt.devandroid.di.module.NetworkModule
 import javax.inject.Singleton
 
 @Singleton
 @Component(modules = arrayOf(
         AndroidSupportInjectionModule::class,
         AppModule::class,
+        NetworkModule::class,
         ActivityModule::class
 ))
 
diff --git a/app/src/main/java/keijumt/devandroid/di/CustomQualifer.kt b/app/src/main/java/keijumt/devandroid/di/CustomQualifer.kt
new file mode 100644
index 0000000..25cf726
--- /dev/null
+++ b/app/src/main/java/keijumt/devandroid/di/CustomQualifer.kt
@@ -0,0 +1,6 @@
+package keijumt.devandroid.di
+
+import javax.inject.Qualifier
+
+@Qualifier
+annotation class RetrofitPostalCode
diff --git a/app/src/main/java/keijumt/devandroid/di/module/AppModule.kt b/app/src/main/java/keijumt/devandroid/di/module/AppModule.kt
index 9ef89c2..354a6b5 100644
--- a/app/src/main/java/keijumt/devandroid/di/module/AppModule.kt
+++ b/app/src/main/java/keijumt/devandroid/di/module/AppModule.kt
@@ -4,6 +4,9 @@
 import android.content.Context
 import dagger.Module
 import dagger.Provides
+import keijumt.devandroid.api.PostalCodeApi
+import keijumt.devandroid.repository.PostalCodeDataRepository
+import keijumt.devandroid.repository.PostalCodeRepository
 import javax.inject.Singleton
 
 /**
@@ -13,11 +16,15 @@
         ViewModelModule::class
 ))
 class AppModule {
-    
+
     @Singleton
     @Provides
     fun provideContext(application: Application): Context {
         return application.applicationContext
     }
 
+    @Singleton
+    @Provides
+    fun providePostalCodeRepository(postalCodeApi: PostalCodeApi): PostalCodeRepository =
+            PostalCodeDataRepository(postalCodeApi)
 }
\ No newline at end of file
diff --git a/app/src/main/java/keijumt/devandroid/di/module/NetworkModule.kt b/app/src/main/java/keijumt/devandroid/di/module/NetworkModule.kt
new file mode 100644
index 0000000..6754f36
--- /dev/null
+++ b/app/src/main/java/keijumt/devandroid/di/module/NetworkModule.kt
@@ -0,0 +1,37 @@
+package keijumt.devandroid.di.module
+
+import dagger.Module
+import dagger.Provides
+import keijumt.devandroid.api.PostalCodeApi
+import keijumt.devandroid.di.RetrofitPostalCode
+import okhttp3.OkHttpClient
+import retrofit2.Retrofit
+import retrofit2.adapter.rxjava2.RxJava2CallAdapterFactory
+import retrofit2.converter.gson.GsonConverterFactory
+import javax.inject.Singleton
+
+@Module
+class NetworkModule {
+
+    @Singleton
+    @Provides
+    fun provideOkHttpClient(): OkHttpClient = OkHttpClient.Builder().build()
+
+    @RetrofitPostalCode
+    @Singleton
+    @Provides
+    fun provideRetrofit(okHttpClient: OkHttpClient): Retrofit {
+        return Retrofit.Builder()
+                .client(okHttpClient)
+                .baseUrl("http://zipcloud.ibsnet.co.jp/api/")
+                .addConverterFactory(GsonConverterFactory.create())
+                .addCallAdapterFactory(RxJava2CallAdapterFactory.createAsync())
+                .build()
+    }
+
+    @Singleton
+    @Provides
+    fun providePostalCodeApi(@RetrofitPostalCode retrofit: Retrofit): PostalCodeApi {
+        return retrofit.create(PostalCodeApi::class.java)
+    }
+}
\ No newline at end of file
diff --git a/app/src/main/java/keijumt/devandroid/repository/PostalCodeDataRepository.kt b/app/src/main/java/keijumt/devandroid/repository/PostalCodeDataRepository.kt
new file mode 100644
index 0000000..065e903
--- /dev/null
+++ b/app/src/main/java/keijumt/devandroid/repository/PostalCodeDataRepository.kt
@@ -0,0 +1,8 @@
+package keijumt.devandroid.repository
+
+import keijumt.devandroid.api.PostalCodeApi
+
+class PostalCodeDataRepository(val postalCodeApi: PostalCodeApi) : PostalCodeRepository {
+
+    override fun search(postalCode: Int) = postalCodeApi.getPostalCode(postalCode)
+}
\ No newline at end of file
diff --git a/app/src/main/java/keijumt/devandroid/repository/PostalCodeRepository.kt b/app/src/main/java/keijumt/devandroid/repository/PostalCodeRepository.kt
new file mode 100644
index 0000000..41d6cff
--- /dev/null
+++ b/app/src/main/java/keijumt/devandroid/repository/PostalCodeRepository.kt
@@ -0,0 +1,8 @@
+package keijumt.devandroid.repository
+
+import io.reactivex.Single
+import keijumt.devandroid.api.response.PostalCode
+
+interface PostalCodeRepository {
+    fun search(postalCode: Int): Single<PostalCode>
+}
\ No newline at end of file