diff --git a/server/src/database/requests.ts b/server/src/database/requests.ts
index 0642a3b1..e1e2efaa 100644
--- a/server/src/database/requests.ts
+++ b/server/src/database/requests.ts
@@ -183,3 +183,19 @@ export async function getMatchedUser(userId: UserID): Promise<Result<User[]>> {
     return Err(e);
   }
 }
+
+export async function matchWithMemo(userId: UserID) {
+  try {
+    const result = await prisma.relationship.create({
+      data: {
+        status: "MATCHED",
+        sendingUserId: userId,
+        receivingUserId: 0, //KeepメモのUserId
+      },
+    });
+
+    return result;
+  } catch (error) {
+    return Err(error);
+  }
+}
diff --git a/server/src/router/users.ts b/server/src/router/users.ts
index ae0dd6b3..5be8fcf8 100644
--- a/server/src/router/users.ts
+++ b/server/src/router/users.ts
@@ -9,6 +9,7 @@ import express, { type Request, type Response } from "express";
 import {
   getPendingRequestsFromUser,
   getPendingRequestsToUser,
+  matchWithMemo,
 } from "../database/requests";
 import {
   createUser,
@@ -124,10 +125,20 @@ router.get("/id/:id", async (req: Request, res: Response) => {
 // INSERT INTO "User" VALUES (body...)
 router.post("/", async (req: Request, res: Response) => {
   const partialUser = InitUserSchema.safeParse(req.body);
-  if (!partialUser.success) return res.status(400).send("invalid format");
+  if (!partialUser.success)
+    return res.status(400).send({
+      error: "Invalid input format",
+      details: partialUser.error.errors,
+    });
 
   const user = await createUser(partialUser.data);
-  if (!user.ok) return res.status(500).send();
+  if (!user.ok) return res.status(500).send({ error: "Failed to create user" });
+
+  //ユーザー作成と同時にメモとマッチング
+  const result = await matchWithMemo(user.value.id);
+  if ("ok" in result && !result.ok) {
+    return res.status(500).send({ error: "Failed to match user with memo" });
+  }
   res.status(201).json(user.value);
 });
 
diff --git a/web/components/match/matching.tsx b/web/components/match/matching.tsx
index c38d7c39..c15962f3 100644
--- a/web/components/match/matching.tsx
+++ b/web/components/match/matching.tsx
@@ -25,17 +25,24 @@ export default function Matchings() {
         <p className="text-red-500">Error: {error.message}</p>
       ) : (
         <ul className="mt-4 space-y-4">
-          {data?.map((matchedUser) => (
-            <HumanListItem
-              key={matchedUser.id}
-              id={matchedUser.id}
-              name={matchedUser.name}
-              pictureUrl={matchedUser.pictureUrl}
-              onOpen={() => openModal(matchedUser)}
-              onDelete={() => deleteMatch(matchedUser.id).then(() => reload())}
-              hasDots
-            />
-          ))}
+          {data?.map((matchedUser) =>
+            matchedUser.id === 0 ? (
+              //メモ帳
+              <div key={0} />
+            ) : (
+              <HumanListItem
+                key={matchedUser.id}
+                id={matchedUser.id}
+                name={matchedUser.name}
+                pictureUrl={matchedUser.pictureUrl}
+                onOpen={() => openModal(matchedUser)}
+                onDelete={() =>
+                  deleteMatch(matchedUser.id).then(() => reload())
+                }
+                hasDots
+              />
+            ),
+          )}
         </ul>
       )}
     </div>