diff --git a/src/main/java/com/example/cosmos_serversb/entities/Group.java b/src/main/java/com/example/cosmos_serversb/entities/Group.java
index f600d03..4508c5d 100644
--- a/src/main/java/com/example/cosmos_serversb/entities/Group.java
+++ b/src/main/java/com/example/cosmos_serversb/entities/Group.java
@@ -1,13 +1,17 @@
 //このクラスは仮です
 package com.example.cosmos_serversb.entities;
 
+import com.example.cosmos_serversb.models.Users;
+
 import java.util.ArrayList;
+import java.util.HashSet;
 import java.util.Set;
 
 public class Group {
     private String gId;
     private String uri, name;
-    private Set<User> members;
+    private Set<User> members = new HashSet<>();//HashSetでいいのかな？
+
     //private ArrayList<Request> requests;
     private Set<Request> requests;
 
@@ -80,22 +84,12 @@
         return members;
     }
 
-    /*メンバー*/
-    //public ArrayList<User> getMembersList(){
-    //    return null;
-    //}
-
-    //public void addMemberByUid(String uId){
-    //
-    //    members.add(user);
-    //}
-
-    //public DeleteResult deleteMember(String uid){
-    //    members.remove(members.indexOf(uid));
-    //    return null;
-    //}
-
-    /*リクエスト*/
+    public void addMember(String uId){
+        //User user = new User(uId, uId, "http:test", "sa", "hogehoge");
+        User user = Users.getInstance().getUserById(uId);
+        members.add(user);
+        user.addGroups(this);
+    }
 
 }