diff --git a/src/main/java/org/ntlab/acanthus_server/entities/Account.java b/src/main/java/org/ntlab/acanthus_server/entities/Account.java
index a02616a..dd15d5b 100644
--- a/src/main/java/org/ntlab/acanthus_server/entities/Account.java
+++ b/src/main/java/org/ntlab/acanthus_server/entities/Account.java
@@ -25,7 +25,6 @@
 import com.fasterxml.jackson.annotation.JsonProperty;
 import com.fasterxml.jackson.annotation.JsonPropertyOrder;
 
-import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.UUID;
 
diff --git a/src/main/java/org/ntlab/acanthus_server/resources/accounts/AccountsRest.java b/src/main/java/org/ntlab/acanthus_server/resources/accounts/AccountsRest.java
index 784c4c1..c6ba6c8 100644
--- a/src/main/java/org/ntlab/acanthus_server/resources/accounts/AccountsRest.java
+++ b/src/main/java/org/ntlab/acanthus_server/resources/accounts/AccountsRest.java
@@ -8,8 +8,11 @@
 
 import javax.ws.rs.*;
 import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.Response;
+import javax.ws.rs.core.Response.ResponseBuilder;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.function.Consumer;
 import java.util.regex.Pattern;
 
 @Component
@@ -30,21 +33,16 @@
     public Collection<AccountJson> getAccounts(@QueryParam("name") String name) {
 
         var accountJsonList = new ArrayList<AccountJson>();
+        Consumer<Account> addJson = (account) -> {
+            {
+                var newAccountJson = new AccountJson(account);
+                accountJsonList.add(newAccountJson);
+            }
+        };
 
-        // 名前の一致するアカウントを返す
-        if (name != null) {
-            for (var account : accounts.getAccountsByName(name)) {
-                var newAccountJson = new AccountJson(account);
-                accountJsonList.add(newAccountJson);
-            }
-        }
-        // 全アカウントの取得
-        else {
-            for (var account : accounts.getAllAccounts()) {
-                var newAccountJson = new AccountJson(account);
-                accountJsonList.add(newAccountJson);
-            }
-        }
+        if (name != null) for (var account : accounts.getAccountsByName(name)) addJson.accept(account);  // 名前の一致するアカウントを返す
+        else for (var account : accounts.getAllAccounts()) addJson.accept(account);  // 全アカウントの取得
+
         return accountJsonList;
     }
 
@@ -60,13 +58,23 @@
     @Path("/{uid}")
     @Produces(MediaType.APPLICATION_JSON)
     public Account getAccountByUid(@PathParam("uid") String uidStr, @QueryParam("token") String token) {
+
         var uid = Integer.parseInt(uidStr);
         var searchAccount = accounts.getAccountByUid(uid);
 
-        if (searchAccount == null) throw new WebApplicationException(404);
-        if (!token.equals(searchAccount.getToken())) throw new WebApplicationException(400);
+        var response = Response.status(Response.Status.NO_CONTENT);
 
-        return searchAccount;
+        // アカウントの検索
+        if (searchAccount == null){
+            response = Response.status(404).entity("該当アカウントが存在しません。");
+            throw new WebApplicationException(response.build());
+        }
+
+        // トークンの検証
+        if (!token.equals(searchAccount.getToken())) response = Response.status(400).entity("トークンが違います。");
+        else response.status(200).entity(searchAccount).entity("アカウントが見つかりました。");
+
+        throw new WebApplicationException(response.build());
     }
 
     //-----------------------------------------------------------------
@@ -83,18 +91,24 @@
     @Produces(MediaType.APPLICATION_JSON)
     public int createAccount(@FormParam("name") String name, @FormParam("email") String email, @FormParam("password") String password) {
 
+        ResponseBuilder response = Response.status(0);
+
         // パスワード, メアドが正しく入力されているかチェック
-        if (!isCorrectPassword(password) || !isCorrectEmailAddress(email) || !isCorrectName(name))
-            throw new WebApplicationException(401);
+        if (!isCorrectName(name) || !isCorrectPassword(password) || !isCorrectEmailAddress(email)) {
+            response.status(401).entity("入力に誤りがあります。");
+            throw new WebApplicationException(response.build());
+        }
 
         // すでに同じメールアドレスが存在しているか
         var existAccount = accounts.getAccountByEmail(email);
-        if (existAccount != null) throw new WebApplicationException(400);
+        if (existAccount != null) response.status(400).entity("入力されたメールアドレスは既に使われています。");
+        else {
+            // アカウント登録
+            var newAccount = accounts.registerAccount(name, email, password);
+            response.status(200).entity(newAccount.getUid());
+        }
 
-        // アカウント登録
-        var newAccount = accounts.registerAccount(name, email, password);
-
-        return newAccount.getUid();
+        throw new WebApplicationException(response.build());
     }
 
     //-----------------------------------------------------------------
@@ -105,7 +119,6 @@
     /**
      * @param emailAddress メアド
      */
-    @SuppressWarnings("{unchecked}") // 正規表現の警告無視
     private boolean isCorrectEmailAddress(String emailAddress) {
 
         var aText = "[a-zA-Z0-9_!#¥¥$¥¥%&'*+/=?¥¥^`{}~|¥¥-]+";
diff --git a/src/main/java/org/ntlab/acanthus_server/resources/accounts/LoginRest.java b/src/main/java/org/ntlab/acanthus_server/resources/accounts/LoginRest.java
index ad131cd..adbb211 100644
--- a/src/main/java/org/ntlab/acanthus_server/resources/accounts/LoginRest.java
+++ b/src/main/java/org/ntlab/acanthus_server/resources/accounts/LoginRest.java
@@ -1,10 +1,16 @@
 package org.ntlab.acanthus_server.resources.accounts;
 
+import org.glassfish.jersey.spi.Contract;
 import org.ntlab.acanthus_server.models.Accounts;
+import org.springframework.lang.NonNull;
 import org.springframework.stereotype.Component;
 
+import javax.validation.constraints.NotNull;
 import javax.ws.rs.*;
 import javax.ws.rs.core.MediaType;
+import javax.ws.rs.core.Response;
+import javax.ws.rs.core.Response.ResponseBuilder;
+import java.util.ResourceBundle;
 
 @Component
 @Path("/accounts/login")
@@ -21,13 +27,17 @@
     @GET
     @Produces(MediaType.APPLICATION_JSON)
     public boolean hasLoginToken(@QueryParam("uid") String uidStr, @QueryParam("token") String token) {
+
+        var response = Response.status(Response.Status.NO_CONTENT);
         var uid = Integer.parseInt(uidStr);
         var searchAccount = accounts.getAccountByUid(uid);
 
-        if (searchAccount == null) throw new WebApplicationException(404);
-        if (!token.equals(searchAccount.getToken())) throw new WebApplicationException(400);
+        // アカウントとトークンの検証
+        if (searchAccount == null) response.status(404).entity(false);
+        if (!token.equals(searchAccount.getToken())) response.status(400).entity(false);
+        else response.status(200).entity(true);
 
-        throw new WebApplicationException(200);
+        throw new WebApplicationException(response.build());
     }
 
     //-----------------------------------------------------------
@@ -42,13 +52,18 @@
     @Produces(MediaType.APPLICATION_JSON)
     public String issueLoginToken(@FormParam("email") String email, @FormParam("password") String password) {
 
+        var response = Response.status(Response.Status.NO_CONTENT);
         var searchAccount = accounts.getAccountByEmail(email);
 
-        if (searchAccount == null) throw new WebApplicationException(400);
-        if (!searchAccount.isMatchedPassword(password)) throw new WebApplicationException(401);
+        if (searchAccount == null) response.status(404).entity("アカウントが存在しません。");
+        if (!searchAccount.isMatchedPassword(password)) response.entity(401).entity("不正なパスワードです。");
+        else {
+            // トークンをアカウントに設定
+            searchAccount.updateToken();
+            response.status(201).entity(searchAccount.getToken());
+        }
 
-        searchAccount.updateToken(); // トークンをアカウントに設定
-        return searchAccount.getToken();
+        throw new WebApplicationException(response.build());
     }
     //-----------------------------------------------------------