diff --git a/schema/migrate/M0010-cm-user-duel-list.sql b/schema/migrate/M0010-cm-user-duel-list.sql
new file mode 100644
index 0000000..ff561cd
--- /dev/null
+++ b/schema/migrate/M0010-cm-user-duel-list.sql
@@ -0,0 +1,16 @@
+create table "cm_user_duel_list" (
+    "id" integer primary key not null,
+    "profile_id" integer not null
+            references "cm_user_data"("id")
+            on delete cascade,
+    "duel_id" integer not null,
+    "progress" integer not null,
+    "point" integer not null,
+    "is_clear" boolean not null,
+    "last_play_date" text not null,
+    "param1" integer not null,
+    "param2" integer not null,
+    "param3" integer not null,
+    "param4" integer not null,
+    constraint "cm_user_duel_list_uq" unique ("profile_id", "duel_id")
+);
diff --git a/src/chunithm/handler/getUserDuel.ts b/src/chunithm/handler/getUserDuel.ts
index 8a05453..045b3f5 100644
--- a/src/chunithm/handler/getUserDuel.ts
+++ b/src/chunithm/handler/getUserDuel.ts
@@ -1,14 +1,23 @@
 import { Repositories } from "../repo";
 import { GetUserDuelRequest } from "../request/getUserDuel";
 import { GetUserDuelResponse } from "../response/getUserDuel";
+import { readAimeId } from "../proto/base";
+import { writeUserDuelList } from "../proto/userDuelList";
 
 export default async function getUserDuel(
   rep: Repositories,
   req: GetUserDuelRequest
 ): Promise<GetUserDuelResponse> {
+  const aimeId = readAimeId(req.userId);
+  // Get all duel entities if the client specifies to.
+  const duelId = req.isAllDuel ? undefined : parseInt(req.duelId);
+
+  const profileId = await rep.userData().lookup(aimeId);
+  const items = await rep.userDuelList().load(profileId, duelId);
+
   return {
     userId: req.userId,
-    length: "0",
-    userDuelList: [],
+    length: items.length.toString(),
+    userDuelList: items.map(writeUserDuelList),
   };
 }
diff --git a/src/chunithm/handler/upsertUserAll.ts b/src/chunithm/handler/upsertUserAll.ts
index d0836a9..e9d1642 100644
--- a/src/chunithm/handler/upsertUserAll.ts
+++ b/src/chunithm/handler/upsertUserAll.ts
@@ -11,6 +11,7 @@ import { readUserItem } from "../proto/userItem";
 import { readUserMusicDetail } from "../proto/userMusic";
 import { readUserActivity } from "../proto/userActivity";
 import { readUserDataEx } from "../proto/userDataEx";
+import { readUserDuelList } from "../proto/userDuelList";
 import { readUserPlaylog } from "../proto/userPlaylog";
 
 // It shouldn't need to be said really, but seeing as this message (A) requires
@@ -69,5 +70,9 @@ export default async function upsertUserAll(
     await rep.userDataEx().save(profileId, readUserDataEx(item));
   }
 
+  for (const item of payload.userDuelList || []) {
+    await rep.userDuelList().save(profileId, readUserDuelList(item));
+  }
+
   return { returnCode: "1" };
 }
diff --git a/src/chunithm/model/userDuelList.ts b/src/chunithm/model/userDuelList.ts
new file mode 100644
index 0000000..70cc5bc
--- /dev/null
+++ b/src/chunithm/model/userDuelList.ts
@@ -0,0 +1,11 @@
+export interface UserDuelListItem {
+  duelId: number;
+  progress: number;
+  point: number;
+  isClear: boolean;
+  lastPlayDate: Date;
+  param1: number;
+  param2: number;
+  param3: number;
+  param4: number;
+}
diff --git a/src/chunithm/proto/userDuelList.ts b/src/chunithm/proto/userDuelList.ts
new file mode 100644
index 0000000..6c0c072
--- /dev/null
+++ b/src/chunithm/proto/userDuelList.ts
@@ -0,0 +1,26 @@
+import { Crush, readBoolean, readDate, writeObject } from "./base";
+import { UserDuelListItem } from "../model/userDuelList";
+
+export type UserDuelListJson = Crush<UserDuelListItem>;
+
+export function readUserDuelList(
+  json: UserDuelListJson
+): UserDuelListItem {
+  return {
+    duelId: parseInt(json.duelId),
+    progress: parseInt(json.progress),
+    point: parseInt(json.point),
+    isClear: readBoolean(json.isClear),
+    lastPlayDate: readDate(json.lastPlayDate),
+    param1: parseInt(json.param1),
+    param2: parseInt(json.param2),
+    param3: parseInt(json.param3),
+    param4: parseInt(json.param4),
+  };
+}
+
+export function writeUserDuelList(
+  obj: UserDuelListItem
+): UserDuelListJson {
+  return writeObject(obj);
+}
diff --git a/src/chunithm/repo/index.ts b/src/chunithm/repo/index.ts
index 6486a21..c162911 100644
--- a/src/chunithm/repo/index.ts
+++ b/src/chunithm/repo/index.ts
@@ -4,6 +4,7 @@ import { UserActivityRepository } from "./userActivity";
 import { UserCharacterRepository } from "./userCharacter";
 import { UserDataRepository } from "./userData";
 import { UserDataExRepository } from "./userDataEx";
+import { UserDuelListRepository } from "./userDuelList";
 import { UserGameOptionRepository } from "./userGameOption";
 import { UserGameOptionExRepository } from "./userGameOptionEx";
 import { UserItemRepository } from "./userItem";
@@ -20,6 +21,8 @@ export interface Repositories {
 
   userDataEx(): UserDataExRepository;
 
+  userDuelList(): UserDuelListRepository;
+
   userGameOption(): UserGameOptionRepository;
 
   userGameOptionEx(): UserGameOptionExRepository;
diff --git a/src/chunithm/repo/userDuelList.ts b/src/chunithm/repo/userDuelList.ts
new file mode 100644
index 0000000..da673bd
--- /dev/null
+++ b/src/chunithm/repo/userDuelList.ts
@@ -0,0 +1,13 @@
+import { Page } from "./_defs";
+import { UserDataItem } from "../model/userData";
+import { UserDuelListItem } from "../model/userDuelList";
+import { Id } from "../../model";
+
+export interface UserDuelListRepository {
+  load(
+    profileId: Id<UserDataItem>,
+    duelId?: number,
+  ): Promise<UserDuelListItem[]>;
+
+  save(profileId: Id<UserDataItem>, obj: UserDuelListItem): Promise<void>;
+}
diff --git a/src/chunithm/request/upsertUserAll.ts b/src/chunithm/request/upsertUserAll.ts
index b7ee95b..72a0a02 100644
--- a/src/chunithm/request/upsertUserAll.ts
+++ b/src/chunithm/request/upsertUserAll.ts
@@ -9,6 +9,7 @@ import { UserActivityJson } from "../proto/userActivity";
 import { UserRecentRatingJson } from "../proto/userRecentRating";
 import { UserPlaylogJson } from "../proto/userPlaylog";
 import { UserDataExJson } from "../proto/userDataEx";
+import { UserDuelListJson } from "../proto/userDuelList";
 
 export interface UpsertUserAllRequest {
   /** Integer, AiMe ID */
@@ -26,6 +27,7 @@ export interface UpsertUserAllRequest {
     userRecentRatingList?: UserRecentRatingJson[];
     userPlaylogList?: UserPlaylogJson[];
     userDataEx?: UserDataExJson[];
+    userDuelList?: UserDuelListJson[];
 
     /** String of binary digits */
     isNewMapList: string;
diff --git a/src/chunithm/response/getUserDuel.ts b/src/chunithm/response/getUserDuel.ts
index e419ce5..40deb90 100644
--- a/src/chunithm/response/getUserDuel.ts
+++ b/src/chunithm/response/getUserDuel.ts
@@ -1,3 +1,5 @@
+import { UserDuelListJson } from "../proto/userDuelList";
+
 export interface GetUserDuelResponse {
   /** Integer, AiMe ID */
   userId: string;
@@ -5,6 +7,9 @@ export interface GetUserDuelResponse {
   /** Integer, number of results returned */
   length: string;
 
-  /** TBD */
-  userDuelList: [];
+  /**
+   * List of duel entities, either all duel entities associated with `userId`
+   * or single requested by `duelId` in request.
+   */
+  userDuelList: UserDuelListJson[];
 }
diff --git a/src/chunithm/sql/_factory.ts b/src/chunithm/sql/_factory.ts
index d6d85d4..8acab3b 100644
--- a/src/chunithm/sql/_factory.ts
+++ b/src/chunithm/sql/_factory.ts
@@ -2,6 +2,7 @@ import { SqlUserActivityRepository } from "./userActivity";
 import { SqlUserCharacterRepository } from "./userCharacter";
 import { SqlUserDataRepository } from "./userData";
 import { SqlUserDataExRepository } from "./userDataEx";
+import { SqlUserDuelListRepository } from "./userDuelList";
 import { SqlUserGameOptionRepository } from "./userGameOption";
 import { SqlUserGameOptionExRepository } from "./userGameOptionEx";
 import { SqlUserItemRepository } from "./userItem";
@@ -13,6 +14,7 @@ import { UserActivityRepository } from "../repo/userActivity";
 import { UserCharacterRepository } from "../repo/userCharacter";
 import { UserDataRepository } from "../repo/userData";
 import { UserDataExRepository } from "../repo/userDataEx";
+import { UserDuelListRepository } from "../repo/userDuelList";
 import { UserGameOptionRepository } from "../repo/userGameOption";
 import { UserGameOptionExRepository } from "../repo/userGameOptionEx";
 import { UserItemRepository } from "../repo/userItem";
@@ -40,6 +42,10 @@ export class SqlRepositories implements Repositories {
     return new SqlUserDataExRepository(this._txn);
   }
 
+  userDuelList(): UserDuelListRepository {
+    return new SqlUserDuelListRepository(this._txn);
+  }
+
   userGameOption(): UserGameOptionRepository {
     return new SqlUserGameOptionRepository(this._txn);
   }
diff --git a/src/chunithm/sql/userDuelList.ts b/src/chunithm/sql/userDuelList.ts
new file mode 100644
index 0000000..db2b074
--- /dev/null
+++ b/src/chunithm/sql/userDuelList.ts
@@ -0,0 +1,56 @@
+import sql from "sql-bricks-postgres";
+
+import { UserDataItem } from "../model/userData";
+import { UserDuelListItem } from "../model/userDuelList";
+import { Page } from "../repo";
+import { UserDuelListRepository } from "../repo/userDuelList";
+import { Id } from "../../model";
+import { Transaction } from "../../sql";
+import { T, createSqlMapper } from "../../sql/util";
+
+const { readRow, writeRow, colNames } = createSqlMapper({
+  duelId: T.number,
+  progress: T.number,
+  point: T.number,
+  isClear: T.boolean,
+  lastPlayDate: T.Date,
+  param1: T.number,
+  param2: T.number,
+  param3: T.number,
+  param4: T.number,
+});
+
+export class SqlUserDuelListRepository implements UserDuelListRepository {
+  constructor(private readonly _txn: Transaction) {}
+
+  async load(
+    profileId: Id<UserDataItem>,
+    duelId?: number
+  ): Promise<UserDuelListItem[]> {
+    const stmt = sql
+      .select("*")
+      .from("cm_user_duel_list")
+      .where("profile_id", profileId);
+
+    if (duelId !== undefined) {
+      stmt.where("duel_id", duelId);
+    }
+
+    const rows = await this._txn.fetchRows(stmt);
+
+    return rows.map(readRow);
+  }
+
+  save(profileId: Id<UserDataItem>, obj: UserDuelListItem): Promise<void> {
+    const stmt = sql
+      .insert("cm_user_duel_list", {
+        id: this._txn.generateId(),
+        profile_id: profileId,
+        ...writeRow(obj),
+      })
+      .onConflict("profile_id", "duel_id")
+      .doUpdate(colNames);
+
+    return this._txn.modify(stmt);
+  }
+}