diff --git a/.idea/misc.xml b/.idea/misc.xml
index bc8d0a3..7e13a7a 100644
--- a/.idea/misc.xml
+++ b/.idea/misc.xml
@@ -1,7 +1,10 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project version="4">
   <component name="ExternalStorageConfigurationManager" enabled="true" />
-  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" project-jdk-name="1.8" project-jdk-type="JavaSDK">
+  <component name="JavaScriptSettings">
+    <option name="languageLevel" value="ES6" />
+  </component>
+  <component name="ProjectRootManager" version="2" languageLevel="JDK_1_8" default="false" project-jdk-name="12" project-jdk-type="JavaSDK">
     <output url="file://$PROJECT_DIR$/out" />
   </component>
 </project>
\ No newline at end of file
diff --git a/src/main/java/com/example/cosmos_serversb/entities/Group.java b/src/main/java/com/example/cosmos_serversb/entities/Group.java
new file mode 100644
index 0000000..50e19c2
--- /dev/null
+++ b/src/main/java/com/example/cosmos_serversb/entities/Group.java
@@ -0,0 +1,67 @@
+//このクラスは仮です
+package com.example.cosmos_serversb.entities;
+
+import java.util.ArrayList;
+
+public class Group {
+    private String gId, uri, name;
+    //private ArrayList<User> members;
+    private ArrayList<Request> requests;
+
+
+    private Group(){
+
+    }
+
+    public Group(String gId, String uri, String name, String uId){
+        setGid(gId);
+        setUri(uri);
+        setName(name);
+        //addMemberByUid(uId);
+    }
+
+    private void setGid(String gId){
+        this.gId = gId;
+    }
+
+    public String getGid(){
+        return gId;
+    }
+
+    private void setUri(String uri){
+        this.uri = uri;
+    }
+
+    public String getUriByGid(String gId){
+        return uri;
+    }
+
+    public void setName(String name){
+        this.name = name;
+    }
+
+    public String getNameByGid(String gId){
+        return name;
+    }
+
+    /*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*/
+//
+
+
+}
+
diff --git a/src/main/java/com/example/cosmos_serversb/entities/Request.java b/src/main/java/com/example/cosmos_serversb/entities/Request.java
new file mode 100644
index 0000000..23e9280
--- /dev/null
+++ b/src/main/java/com/example/cosmos_serversb/entities/Request.java
@@ -0,0 +1,42 @@
+//このクラスは仮です
+package com.example.cosmos_serversb.entities;
+
+public class Request {
+    private String rId, uri, date, IssuerUid, product, deadline;
+    private int location;// YahooローカルサーチAPIの業種コード
+    private boolean done;
+
+//    private Request(){
+//
+//    }
+
+//    public Request(){
+//
+//    }
+
+    private void setRid(String rId){
+        this.rId = rId;
+    }
+
+    public String getRid(){
+        return rId;
+    }
+
+    private void setUri(String uri){
+        this.uri = uri;
+    }
+
+    public String getUri(){
+        return uri;
+    }
+
+    public void setIssuerUid(String IssuerUid){
+        this.IssuerUid = IssuerUid;
+    }
+
+    public String getIssuerUid(){
+        return IssuerUid;
+    }
+
+
+}
diff --git a/src/main/java/com/example/cosmos_serversb/models/Groups.java b/src/main/java/com/example/cosmos_serversb/models/Groups.java
new file mode 100644
index 0000000..0c7b42e
--- /dev/null
+++ b/src/main/java/com/example/cosmos_serversb/models/Groups.java
@@ -0,0 +1,75 @@
+package com.example.cosmos_serversb.models;
+
+
+import java.util.*;
+import javax.inject.Singleton;
+import com.example.cosmos_serversb.entities.*;
+
+
+@Singleton
+public class Groups {
+    private static Groups thaInstance = null;
+    private ArrayList<Group> accounts = new ArrayList<>();
+
+    private Groups(){
+
+    }
+
+    public static Groups getInstance(){
+        if(thaInstance == null){
+            thaInstance = new Groups();
+        }
+        return thaInstance;
+    }
+
+
+    public HashMap<String, String> getGroupsListByUid(String uId){
+        return null;
+    }
+
+    public Group createGroup(String name, String uId){
+        return null;
+    }
+
+    public Group getGroupByGid(String gId){
+        return null;
+    }
+
+    public DeleteResult deleteGroup(String gId){
+        return null;
+    }
+
+    public HashMap<String, String> getMembersListByGid(String gId){
+        return null;
+    }
+
+    public HashMap<String, String> addMember(String gId, String uId){
+        return null;
+    }
+
+    public HashMap<String, String> deleteMember(String gId){
+        return null;
+    }
+
+    public HashMap<String, String> getRequestsListByGid(String gId){
+        return null;
+    }
+
+    public Request addRequests(String gId, String uId, String product,
+                                    String deadline, int location){
+        return null;
+    }
+
+    public Request getRequestDetailByGidAndRid(String gId, String rId){
+        return null;
+    }
+
+    public Request updateRequest(String gId, String rId, String uId, String product,
+                                    String deadline, int location, boolean done){
+        return null;
+    }
+
+    public DeleteResult deleteRequest(String gId, String rId){
+        return null;
+    }
+}