diff --git a/.idea/misc.xml b/.idea/misc.xml
index 860da66..d5d35ec 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_11" default="true" project-jdk-name="1.8" project-jdk-type="JavaSDK">
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" default="true" project-jdk-name="1.8" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/build/classes" />
   </component>
   <component name="ProjectType">
diff --git a/app/src/main/java/org/ntlab/acanthus_client/entities/Account.java b/app/src/main/java/org/ntlab/acanthus_client/entities/Account.java
new file mode 100644
index 0000000..53c4b44
--- /dev/null
+++ b/app/src/main/java/org/ntlab/acanthus_client/entities/Account.java
@@ -0,0 +1,17 @@
+package org.ntlab.acanthus_client.entities;
+
+import java.time.LocalDateTime;
+import java.util.HashMap;
+
+//-----------------------------------------------------------------
+// ユーザーアカウント
+public class Account {
+    private Integer uid;
+    private String name;
+    private String email;
+    private String password;
+    private String token;
+    private HashMap<Integer,Work> workHashMap = new HashMap<>();
+    private Boolean isDummy;
+    private LocalDateTime lastAccess;
+}
diff --git a/app/src/main/java/org/ntlab/acanthus_client/entities/AccountJson.java b/app/src/main/java/org/ntlab/acanthus_client/entities/AccountJson.java
new file mode 100644
index 0000000..c6728f9
--- /dev/null
+++ b/app/src/main/java/org/ntlab/acanthus_client/entities/AccountJson.java
@@ -0,0 +1,8 @@
+package org.ntlab.acanthus_client.entities;
+
+//-----------------------------------------------------------------
+// 全ユーザー検索時情報
+public class AccountJson {
+    private Integer uid;
+    private String name;
+}
diff --git a/app/src/main/java/org/ntlab/acanthus_client/entities/AccountTokenJson.java b/app/src/main/java/org/ntlab/acanthus_client/entities/AccountTokenJson.java
new file mode 100644
index 0000000..bb76238
--- /dev/null
+++ b/app/src/main/java/org/ntlab/acanthus_client/entities/AccountTokenJson.java
@@ -0,0 +1,7 @@
+package org.ntlab.acanthus_client.entities;
+
+//-----------------------------------------------------------------
+// アカウントに発行されたトークン
+public class AccountTokenJson {
+    private String token;
+}
diff --git a/app/src/main/java/org/ntlab/acanthus_client/entities/AccountUidJson.java b/app/src/main/java/org/ntlab/acanthus_client/entities/AccountUidJson.java
new file mode 100644
index 0000000..35d81b9
--- /dev/null
+++ b/app/src/main/java/org/ntlab/acanthus_client/entities/AccountUidJson.java
@@ -0,0 +1,7 @@
+package org.ntlab.acanthus_client.entities;
+
+//-----------------------------------------------------------------
+// アカウントのUid
+public class AccountUidJson {
+    private Integer uid;
+}
diff --git a/app/src/main/java/org/ntlab/acanthus_client/entities/Work.java b/app/src/main/java/org/ntlab/acanthus_client/entities/Work.java
new file mode 100644
index 0000000..849e8ac
--- /dev/null
+++ b/app/src/main/java/org/ntlab/acanthus_client/entities/Work.java
@@ -0,0 +1,4 @@
+package org.ntlab.acanthus_client.entities;
+
+public class Work {
+}
diff --git a/app/src/main/java/org/ntlab/acanthus_client/resources/accounts/AccountsRest.java b/app/src/main/java/org/ntlab/acanthus_client/resources/accounts/AccountsRest.java
new file mode 100644
index 0000000..eb5af07
--- /dev/null
+++ b/app/src/main/java/org/ntlab/acanthus_client/resources/accounts/AccountsRest.java
@@ -0,0 +1,44 @@
+package org.ntlab.acanthus_client.resources.accounts;
+
+import org.ntlab.acanthus_client.entities.Account;
+import org.ntlab.acanthus_client.entities.AccountJson;
+import org.ntlab.acanthus_client.entities.AccountUidJson;
+
+import java.util.Collection;
+
+import retrofit2.Call;
+import retrofit2.http.Field;
+import retrofit2.http.FormUrlEncoded;
+import retrofit2.http.GET;
+import retrofit2.http.POST;
+import retrofit2.http.Path;
+import retrofit2.http.Query;
+
+//-----------------------------------------------------------------
+// RestAPI: accounts, accounts/{uid}
+public interface AccountsRest {
+    //-----------------------------------------------------------------
+    // 全ユーザーの uid/name を取得
+    @GET("accounts")
+    Call<Collection<AccountJson>> getAccounts(
+            @Query("name") String name
+    );
+    //-----------------------------------------------------------------
+    // アカウントの新規作成
+    @FormUrlEncoded
+    @POST("accounts")
+    Call<AccountUidJson> createAccount(
+            @Field("name")String name,
+            @Field("email")String email,
+            @Field("password")String password
+    );
+    //-----------------------------------------------------------------
+    // 対応するuidのユーザーの取得
+    @GET("accounts/{uid}")
+    Call<Account> getAccountByUid(
+            @Path("uid")String uidStr,
+            @Query("token")String token
+    );
+    //-----------------------------------------------------------------
+
+}
diff --git a/app/src/main/java/org/ntlab/acanthus_client/resources/accounts/LoginRest.java b/app/src/main/java/org/ntlab/acanthus_client/resources/accounts/LoginRest.java
new file mode 100644
index 0000000..a70eece
--- /dev/null
+++ b/app/src/main/java/org/ntlab/acanthus_client/resources/accounts/LoginRest.java
@@ -0,0 +1,34 @@
+package org.ntlab.acanthus_client.resources.accounts;
+
+import org.ntlab.acanthus_client.entities.AccountJson;
+import org.ntlab.acanthus_client.entities.AccountTokenJson;
+
+import retrofit2.Call;
+import retrofit2.http.Field;
+import retrofit2.http.FormUrlEncoded;
+import retrofit2.http.GET;
+import retrofit2.http.PUT;
+import retrofit2.http.Query;
+
+//-----------------------------------------------------------------
+// RestAPI: accounts/login
+public interface LoginRest {
+
+    //-----------------------------------------------------------------
+    // トークン認証
+    @GET("accounts/login")
+    Call<Boolean> hasLoginToken(
+            @Query("uid") String uidStr,
+            @Query("token") String token
+    );
+
+    //-----------------------------------------------------------------
+    // トークンの発行
+    @FormUrlEncoded
+    @PUT("accounts/login")
+    Call<AccountTokenJson> issueLoginToken(
+            @Field("email")String email,
+            @Field("password")String password
+    );
+    //-----------------------------------------------------------------
+}