diff --git a/src/main/java/org/ntlab/tampoposerver/repositories/ChatRequestRepository.java b/src/main/java/org/ntlab/tampoposerver/repositories/ChatRequestRepository.java
index d45cbb8..08960c5 100644
--- a/src/main/java/org/ntlab/tampoposerver/repositories/ChatRequestRepository.java
+++ b/src/main/java/org/ntlab/tampoposerver/repositories/ChatRequestRepository.java
@@ -3,7 +3,6 @@
 import org.ntlab.tampoposerver.models.ChatRequest;
 import org.springframework.stereotype.Repository;
 
-import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 
@@ -13,19 +12,36 @@
     private int id = 0;
 
     public ChatRequest addChatRequest(String senderId, String receiverId) {
-        return null;
+        ChatRequest chatRequest = new ChatRequest(id, senderId, receiverId);
+        chatRequests.put(id, chatRequest);
+        id++;
+        return chatRequest;
     }
 
     public ChatRequest getChatRequest(int chatRequestId) {
         return chatRequests.get(chatRequestId);
     }
 
-    public ArrayList<ChatRequest> getChatRequestsForUser(String userId) {
-        return null;
+    public List<ChatRequest> getChatRequestsForUser(String userId) {
+        if(userId == null) {
+            return null;
+        }
+        List<ChatRequest> chatRequestsForUser;
+        chatRequestsForUser = chatRequests.values().stream().filter(chatReq -> chatReq.getReceiverId().equals(userId) || chatReq.getSenderId().equals(userId)).toList();
+        if(chatRequestsForUser.isEmpty()) {
+            return null;
+        }
+        return chatRequestsForUser;
     }
 
     public ChatRequest deleteChatRequest(int chatRequestId) {
-        return null;
+        ChatRequest chatRequest = chatRequests.get(chatRequestId);
+        if(chatRequest == null) {
+            return null;
+        }
+
+        chatRequest = chatRequests.remove(chatRequestId);
+        return chatRequest;
     }
 
 }
diff --git a/src/test/java/org/ntlab/tampoposerver/models/ChatRequestTest.java b/src/test/java/org/ntlab/tampoposerver/models/ChatRequestTest.java
new file mode 100644
index 0000000..4886c25
--- /dev/null
+++ b/src/test/java/org/ntlab/tampoposerver/models/ChatRequestTest.java
@@ -0,0 +1,33 @@
+package org.ntlab.tampoposerver.models;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+public class ChatRequestTest {
+
+    @Test
+    void contextLoads() {
+        ChatRequest c1 = new ChatRequest(0,"u02","u01");
+        ChatRequest c2 = new ChatRequest(1,"u01","u02");
+        assertEquals(0, c1.getChatRequestId());
+        assertEquals("u02", c1.getSenderId());
+        assertEquals("u01", c1.getReceiverId());
+        assertEquals(1, c2.getChatRequestId());
+        assertEquals("u01", c2.getSenderId());
+        assertEquals("u02", c2.getReceiverId());
+
+        c1.setChatRequestId(2);
+        c1.setSenderId("u01");
+        c1.setReceiverId("u02");
+        c2.setChatRequestId(3);
+        c2.setSenderId("u02");
+        c2.setReceiverId("u01");
+        assertEquals(2, c1.getChatRequestId());
+        assertEquals("u01", c1.getSenderId());
+        assertEquals("u02", c1.getReceiverId());
+        assertEquals(3, c2.getChatRequestId());
+        assertEquals("u02", c2.getSenderId());
+        assertEquals("u01", c2.getReceiverId());
+    }
+}
diff --git a/src/test/java/org/ntlab/tampoposerver/repositories/ChatRequestRepositoryTest.java b/src/test/java/org/ntlab/tampoposerver/repositories/ChatRequestRepositoryTest.java
new file mode 100644
index 0000000..123bf3e
--- /dev/null
+++ b/src/test/java/org/ntlab/tampoposerver/repositories/ChatRequestRepositoryTest.java
@@ -0,0 +1,66 @@
+package org.ntlab.tampoposerver.repositories;
+
+import com.fasterxml.jackson.core.JsonProcessingException;
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.datatype.jsr310.JavaTimeModule;
+import org.junit.jupiter.api.Test;
+import org.ntlab.tampoposerver.models.ChatRequest;
+import org.springframework.boot.test.context.SpringBootTest;
+
+import java.util.List;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+@SpringBootTest
+public class ChatRequestRepositoryTest {
+
+    @Test
+    void contestLoads() throws JsonProcessingException {
+        ChatRequestRepository chatRequestRepository = new ChatRequestRepository();
+
+        //addとgetのテスト
+        ChatRequest chatRequest1 = chatRequestRepository.addChatRequest("u1","u2");
+        ChatRequest chatRequest2 = chatRequestRepository.addChatRequest("u2","u3");
+        ChatRequest chatRequest3 = chatRequestRepository.addChatRequest("u3","u4");
+
+        ChatRequest c1 = chatRequestRepository.getChatRequest(0);
+        ChatRequest c2 = chatRequestRepository.getChatRequest(1);
+        ChatRequest c3 = chatRequestRepository.getChatRequest(2);
+        ChatRequest c_null1 = chatRequestRepository.getChatRequest(-1);
+        assertEquals(chatRequest1, c1);
+        assertEquals(chatRequest2, c2);
+        assertEquals(chatRequest3, c3);
+        assertNotEquals(chatRequest1, c2);
+        assertNotNull(c1);
+        assertNull(c_null1);
+
+        //Listのgetテスト
+        List<ChatRequest> list1 = chatRequestRepository.getChatRequestsForUser("u2");
+        List<ChatRequest> list_null1 = chatRequestRepository.getChatRequestsForUser("u0");
+        assertNotNull(list1);
+        assertNull(list_null1);
+
+        //Jsonでの表示テスト
+        ObjectMapper mapper = new ObjectMapper();
+        mapper.registerModule(new JavaTimeModule());
+        mapper.findAndRegisterModules();
+
+        String chatRequestJson = mapper.writerWithDefaultPrettyPrinter().writeValueAsString(list1);
+        System.out.println("u2_list: " + chatRequestJson);
+
+        String singleChatRequestJson = mapper.writerWithDefaultPrettyPrinter().writeValueAsString(
+                chatRequestRepository.getChatRequest(0)
+        );
+        System.out.println("id0,u1 and u2: " + singleChatRequestJson);
+
+        //deleteテスト
+        ChatRequest before = chatRequestRepository.getChatRequest(0);
+        ChatRequest after = chatRequestRepository.deleteChatRequest(0);
+        ChatRequest c_null2 = chatRequestRepository.deleteChatRequest(-1);
+        assertNotNull(after);
+        assertEquals(before, after);
+        assertNull(c_null2);
+        ChatRequest c_null3 = chatRequestRepository.getChatRequest(0);
+        assertNull(c_null3);
+    }
+}