diff --git a/.env.example b/.env.example
index 6c5e8ea..7e752b1 100644
--- a/.env.example
+++ b/.env.example
@@ -25,6 +25,13 @@ ADMIN_ROLE_ID="1234567890"
 # 昨年度メンバーロールのID（継続メンバー判定に使用）
 RETURNING_MEMBER_ROLE_ID="1234567890"
 
+# 年度メンバーロールのID（例: Member2026）— オンボーディング完了時・バッチ付与で使用
+MEMBER_ROLE_ID=""
+
+# メンバー種別・学年・学部・興味分野のロールは Discord ギルドのロール名で自動マッチング。
+# Discord サーバーのロール名をプロフィール値（例: "理工学部", "Python", "学部3年", "学部生"）と
+# 一致させれば env var の設定なしに自動で付与される。
+
 # 新入生ロールのID と 付与対象の判定基準日時
 # 管理者ページ「参加日時によるロール付与」のフォーム初期値として使用
 # NEW_MEMBER_JOINED_AFTER: ISO 8601 形式（タイムゾーンオフセット付き）
diff --git a/app/api/onboarding/route.ts b/app/api/onboarding/route.ts
index bf1536f..40c7d03 100644
--- a/app/api/onboarding/route.ts
+++ b/app/api/onboarding/route.ts
@@ -9,6 +9,7 @@ import {
   buildAdminOnboardingCompletedNotification,
 } from "@/lib/discord-dm";
 import { checkLineGroupMembership } from "@/lib/line-invite";
+import { syncMemberDiscordRoles } from "@/lib/discord-role";
 
 export async function POST() {
   const session = await auth();
@@ -101,6 +102,14 @@ export async function POST() {
     ).catch((e) => {
       console.error("Failed to notify admin channel (onboarding):", e);
     });
+
+    syncMemberDiscordRoles(session.user.id, {
+      year: updatedMember.yearByFiscal?.[String(new Date().getFullYear())],
+      faculty: updatedMember.enrollments?.find((e) => e.isCurrent)?.faculty,
+      memberType: updatedMember.memberType,
+    }).catch((e) => {
+      console.error("Failed to sync Discord roles (onboarding):", e);
+    });
   }
 
   return NextResponse.json({ success: true });
diff --git a/app/api/optout/rejoin/route.ts b/app/api/optout/rejoin/route.ts
index 039e0bb..dcd2c11 100644
--- a/app/api/optout/rejoin/route.ts
+++ b/app/api/optout/rejoin/route.ts
@@ -4,6 +4,7 @@ import { deleteOptoutSubmission } from "@/lib/discord-optout";
 import { getMember, markMemberRejoined } from "@/lib/members";
 import { sendDiscordDm, buildRejoinCompletedMessage } from "@/lib/discord-dm";
 import { fetchDiscordDisplayName } from "@/lib/discord";
+import { syncMemberDiscordRoles } from "@/lib/discord-role";
 
 export async function POST() {
   const session = await auth();
@@ -24,9 +25,10 @@ export async function POST() {
     );
   }
 
-  // 再加入歓迎 DM (失敗してもレスポンスには影響させない)
+  // 再加入歓迎 DM + ロール同期 (失敗してもレスポンスには影響させない)
+  let member: Awaited<ReturnType<typeof getMember>> = null;
   try {
-    const member = await getMember(discordId);
+    member = await getMember(discordId);
     const displayName =
       member?.discordUsername ??
       member?.nickname ??
@@ -37,5 +39,16 @@ export async function POST() {
     console.error("Failed to send rejoin DM:", e);
   }
 
+  // 退会者ロール削除 + 通常ロール付与 (fire-and-forget)
+  if (member) {
+    syncMemberDiscordRoles(discordId, {
+      year: member.yearByFiscal?.[String(new Date().getFullYear())],
+      faculty: member.enrollments?.find((e) => e.isCurrent)?.faculty,
+      memberType: member.memberType,
+    }).catch((e) => {
+      console.error("Failed to sync Discord roles (rejoin):", e);
+    });
+  }
+
   return NextResponse.json({ success: true });
 }
diff --git a/app/internal/(protected)/admin/page.tsx b/app/internal/(protected)/admin/page.tsx
index 063c4e4..94b1a02 100644
--- a/app/internal/(protected)/admin/page.tsx
+++ b/app/internal/(protected)/admin/page.tsx
@@ -1,6 +1,7 @@
 import Link from "next/link";
 import { getUnregisteredMembers } from "@/lib/admin/actions";
 import { AdminNotificationPanel } from "@/components/admin/notification-panel";
+import { RoleSyncPanel } from "@/components/admin/role-sync-panel";
 import { RoleAssignmentPanel } from "@/components/admin/role-assignment-panel";
 import { Alert, AlertDescription, AlertTitle } from "@/components/ui/alert";
 import { Button } from "@/components/ui/button";
@@ -83,6 +84,14 @@ export default async function AdminPage() {
         )}
       </section>
 
+      <section className="mt-10">
+        <h2 className="text-lg font-semibold mb-4">Discordロール付与</h2>
+        <p className="text-sm text-muted-foreground mb-4">
+          登録済みメンバー全員に年度メンバーロールおよびメンバー種別ロールを一括付与します。
+        </p>
+        <RoleSyncPanel />
+      </section>
+
       <section className="mt-12">
         <h2 className="text-lg font-semibold mb-4">参加日時によるロール付与</h2>
         <p className="text-sm text-muted-foreground mb-4">
diff --git a/app/layout.tsx b/app/layout.tsx
index 9283e8e..72cd907 100644
--- a/app/layout.tsx
+++ b/app/layout.tsx
@@ -1,6 +1,5 @@
 import type React from "react";
 import type { Metadata } from "next";
-import Script from "next/script";
 import { Noto_Sans_JP } from "next/font/google";
 import "./globals.css";
 import Header from "@/components/header";
@@ -70,9 +69,7 @@ export default function RootLayout({
   return (
     <html lang="ja" suppressHydrationWarning>
       <head>
-        <Script
-          id="theme-init"
-          strategy="beforeInteractive"
+        <script
           dangerouslySetInnerHTML={{
             __html: `(function(){try{var t=localStorage.getItem("theme")||"light";if(t==="system")t=matchMedia("(prefers-color-scheme:dark)").matches?"dark":"light";document.documentElement.classList.add(t);document.documentElement.style.colorScheme=t}catch(e){}})()`,
           }}
diff --git a/app/optout/confirm/[discordId]/[exp]/[messageId]/[sig]/page.tsx b/app/optout/confirm/[discordId]/[exp]/[messageId]/[sig]/page.tsx
index 06d5069..f93adba 100644
--- a/app/optout/confirm/[discordId]/[exp]/[messageId]/[sig]/page.tsx
+++ b/app/optout/confirm/[discordId]/[exp]/[messageId]/[sig]/page.tsx
@@ -22,6 +22,7 @@ import {
   buildAdminOptoutNotification,
 } from "@/lib/discord-dm";
 import { fetchDiscordDisplayName } from "@/lib/discord";
+import { syncMemberDiscordRoles } from "@/lib/discord-role";
 import OptoutStatusCard from "@/components/optout/status-card";
 
 export const dynamic = "force-dynamic";
@@ -169,6 +170,11 @@ export default async function OptoutConfirmPage({
     console.error("Failed to notify admin channel (optout):", e);
   }
 
+  // 退会者ロール付与 (fire-and-forget)
+  syncMemberDiscordRoles(discordId, { optedOut: true }).catch((e) => {
+    console.error("Failed to sync Discord roles (optout):", e);
+  });
+
   // 副作用完了後は専用ページへリダイレクト (リロードでも副作用が再走しないように)
   redirect("/optout/done");
 }
diff --git a/components/admin/role-sync-panel.tsx b/components/admin/role-sync-panel.tsx
new file mode 100644
index 0000000..68ec609
--- /dev/null
+++ b/components/admin/role-sync-panel.tsx
@@ -0,0 +1,145 @@
+"use client";
+
+import { useState, useTransition } from "react";
+import {
+  type SyncRolesResult,
+  syncAllMemberDiscordRoles,
+} from "@/lib/admin/actions";
+import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
+import { Button } from "@/components/ui/button";
+import { Alert, AlertDescription, AlertTitle } from "@/components/ui/alert";
+import { ShieldCheck, CheckCircle, AlertCircle, Loader2 } from "lucide-react";
+
+export function RoleSyncPanel() {
+  const [result, setResult] = useState<SyncRolesResult | null>(null);
+  const [isPending, startTransition] = useTransition();
+
+  function handleSync() {
+    setResult(null);
+    startTransition(async () => {
+      const res = await syncAllMemberDiscordRoles();
+      setResult(res);
+    });
+  }
+
+  return (
+    <div className="space-y-4">
+      {result && (
+        <>
+          <Alert variant={result.failed > 0 ? "destructive" : "default"}>
+            {result.failed > 0 ? (
+              <AlertCircle className="h-4 w-4" />
+            ) : (
+              <CheckCircle className="h-4 w-4" />
+            )}
+            <AlertTitle>ロール同期結果</AlertTitle>
+            <AlertDescription>
+              {result.total}件中 {result.success}件成功
+              {result.failed > 0 && `、${result.failed}件失敗`}
+            </AlertDescription>
+          </Alert>
+
+          <div className="rounded-md border text-sm overflow-x-auto">
+            <table className="w-full">
+              <thead>
+                <tr className="border-b bg-muted/50 text-left">
+                  <th className="px-3 py-2 font-medium">メンバー</th>
+                  <th className="px-3 py-2 font-medium">付与</th>
+                  <th className="px-3 py-2 font-medium">削除</th>
+                  <th className="px-3 py-2 font-medium">エラー</th>
+                </tr>
+              </thead>
+              <tbody>
+                {result.details.map((d) => (
+                  <tr
+                    key={d.discordId}
+                    className={
+                      d.errors.length > 0
+                        ? "border-b bg-destructive/10"
+                        : "border-b"
+                    }
+                  >
+                    <td className="px-3 py-2">
+                      <div>{d.discordUsername}</div>
+                      <div className="text-xs text-muted-foreground">
+                        {d.discordId}
+                      </div>
+                    </td>
+                    <td className="px-3 py-2">
+                      {(d.addedRoleNames ?? []).length > 0 ? (
+                        <ul className="space-y-0.5">
+                          {(d.addedRoleNames ?? []).map((name) => (
+                            <li key={name} className="text-xs">
+                              {name}
+                            </li>
+                          ))}
+                        </ul>
+                      ) : (
+                        <span className="text-muted-foreground">—</span>
+                      )}
+                    </td>
+                    <td className="px-3 py-2">
+                      {(d.removedRoleNames ?? []).length > 0 ? (
+                        <ul className="space-y-0.5">
+                          {(d.removedRoleNames ?? []).map((name) => (
+                            <li key={name} className="text-xs text-orange-600">
+                              {name}
+                            </li>
+                          ))}
+                        </ul>
+                      ) : (
+                        <span className="text-muted-foreground">—</span>
+                      )}
+                    </td>
+                    <td className="px-3 py-2">
+                      {d.errors.length > 0 ? (
+                        <ul className="space-y-0.5 text-destructive">
+                          {d.errors.map((e, i) => (
+                            <li key={i} className="text-xs">
+                              {e}
+                            </li>
+                          ))}
+                        </ul>
+                      ) : (
+                        <span className="text-muted-foreground">—</span>
+                      )}
+                    </td>
+                  </tr>
+                ))}
+              </tbody>
+            </table>
+          </div>
+        </>
+      )}
+
+      <Card>
+        <CardHeader>
+          <CardTitle className="text-lg flex items-center gap-2">
+            <ShieldCheck className="h-5 w-5" />
+            Discordロール一括同期
+          </CardTitle>
+        </CardHeader>
+        <CardContent className="space-y-3">
+          <p className="text-sm text-muted-foreground">
+            登録済みメンバー全員の Discord ロールをプロフィールと同期します。
+            メンバー種別・学年・学部・興味分野は Discord
+            サーバーのロール名と自動マッチングし、不要になったロールは削除します。
+            年度メンバーロール（全員共通）は環境変数
+            <code className="text-xs bg-muted px-1 rounded">
+              MEMBER_ROLE_ID
+            </code>
+            で指定してください。
+          </p>
+          <Button onClick={handleSync} disabled={isPending}>
+            {isPending ? (
+              <Loader2 className="h-4 w-4 animate-spin" />
+            ) : (
+              <ShieldCheck className="h-4 w-4" />
+            )}
+            {isPending ? "同期中..." : "全メンバーのロールを同期"}
+          </Button>
+        </CardContent>
+      </Card>
+    </div>
+  );
+}
diff --git a/lib/admin/actions.ts b/lib/admin/actions.ts
index a5fe267..68ae331 100644
--- a/lib/admin/actions.ts
+++ b/lib/admin/actions.ts
@@ -3,13 +3,19 @@
 import { isAdmin } from "@/lib/auth";
 import { getGuildMembers, type DiscordGuildMember } from "@/lib/discord-guild";
 import { getMemberRegistrationStatus } from "@/lib/members";
+import { getDb } from "@/lib/firebase";
 import {
   sendDiscordDm,
   buildRegistrationNudgeMessage,
   buildOnboardingNudgeMessage,
 } from "@/lib/discord-dm";
 import { getOptoutSubmissionIds } from "@/lib/discord-optout";
-import { getDb } from "@/lib/firebase";
+import {
+  syncMemberDiscordRoles,
+  getGuildRoleNameMap,
+  ensureRolesInMap,
+} from "@/lib/discord-role";
+import type { EnrollmentRecord } from "@/types/profile";
 
 export type MemberStatus = "unregistered" | "onboarding";
 
@@ -188,3 +194,132 @@ export async function getAdminMembers(): Promise<AdminMemberRow[]> {
     })
     .sort((a, b) => a.lastName.localeCompare(b.lastName, "ja"));
 }
+
+export type MemberSyncDetail = {
+  discordId: string;
+  discordUsername: string;
+  addedRoleNames: string[];
+  removedRoleNames: string[];
+  errors: string[];
+};
+
+export type SyncRolesResult = {
+  total: number;
+  success: number;
+  failed: number;
+  details: MemberSyncDetail[];
+};
+
+export async function syncAllMemberDiscordRoles(): Promise<SyncRolesResult> {
+  if (!(await isAdmin())) {
+    throw new Error("管理者権限が必要です");
+  }
+
+  const db = getDb();
+  const snap = await db
+    .collection("members")
+    .where("onboardingCompleted", "==", true)
+    .select(
+      "discordUsername",
+      "optedOut",
+      "yearByFiscal",
+      "enrollments",
+      "memberType",
+    )
+    .get();
+
+  const result: SyncRolesResult = {
+    total: 0,
+    success: 0,
+    failed: 0,
+    details: [],
+  };
+
+  const currentYear = String(new Date().getFullYear());
+  const targets = snap.docs.filter((doc) => doc.data().optedOut !== true);
+  result.total = targets.length;
+
+  const roleNameMap = await getGuildRoleNameMap();
+  console.log(
+    `[role-sync] ギルドロール ${roleNameMap.size}件を取得: [${[...roleNameMap.keys()].join(", ")}]`,
+  );
+  console.log(`[role-sync] 対象メンバー: ${result.total}件`);
+
+  // 全メンバーのプロフィール値を集めてまとめてロールを作成（重複作成を防ぐ）
+  const allProfileKeys = new Set<string>();
+  for (const doc of targets) {
+    const { yearByFiscal, enrollments, memberType } = doc.data();
+    if (memberType === "卒業生" || memberType === "その他") {
+      allProfileKeys.add(memberType as string);
+    } else {
+      const year = (yearByFiscal as Record<string, string> | undefined)?.[
+        currentYear
+      ];
+      const faculty = (enrollments as EnrollmentRecord[] | undefined)?.find(
+        (e) => e.isCurrent,
+      )?.faculty;
+      if (year) allProfileKeys.add(year);
+      if (faculty) allProfileKeys.add(faculty);
+    }
+  }
+  await ensureRolesInMap([...allProfileKeys], roleNameMap);
+
+  // ensureRolesInMap で新規作成されたロールも含めて逆引きマップを構築
+  const roleIdToName = new Map(
+    [...roleNameMap].map(([name, id]) => [id, name]),
+  );
+
+  const CONCURRENCY = 2;
+  for (let i = 0; i < targets.length; i += CONCURRENCY) {
+    const batch = targets.slice(i, i + CONCURRENCY);
+    await Promise.all(
+      batch.map(async (doc) => {
+        const { discordUsername, yearByFiscal, enrollments, memberType } =
+          doc.data();
+        const year = (yearByFiscal as Record<string, string> | undefined)?.[
+          currentYear
+        ];
+        const faculty = (enrollments as EnrollmentRecord[] | undefined)?.find(
+          (e) => e.isCurrent,
+        )?.faculty;
+        const roleResult = await syncMemberDiscordRoles(
+          doc.id,
+          { year, faculty, memberType: memberType as string | undefined },
+          roleNameMap,
+        );
+        const detail: MemberSyncDetail = {
+          discordId: doc.id,
+          discordUsername: discordUsername ?? doc.id,
+          addedRoleNames: roleResult.added.map(
+            (id) => roleIdToName.get(id) ?? id,
+          ),
+          removedRoleNames: roleResult.removed.map(
+            (id) => roleIdToName.get(id) ?? id,
+          ),
+          errors: roleResult.errors,
+        };
+        result.details.push(detail);
+        if (roleResult.errors.length > 0) {
+          result.failed++;
+          console.error(
+            `[role-sync] NG ${discordUsername ?? doc.id}: errors=${roleResult.errors.join(" | ")}`,
+          );
+        } else {
+          result.success++;
+          console.log(
+            `[role-sync] OK ${discordUsername ?? doc.id}: added=[${roleResult.added.join(", ") || "なし"}] removed=[${roleResult.removed.join(", ") || "なし"}]`,
+          );
+        }
+      }),
+    );
+
+    if (i + CONCURRENCY < targets.length) {
+      await sleep(1000);
+    }
+  }
+
+  console.log(
+    `[role-sync] 完了: 成功=${result.success}, 失敗=${result.failed}`,
+  );
+  return result;
+}
diff --git a/lib/discord-role.ts b/lib/discord-role.ts
new file mode 100644
index 0000000..602fd06
--- /dev/null
+++ b/lib/discord-role.ts
@@ -0,0 +1,279 @@
+import { MEMBER_TYPES, FACULTIES, GRADUATE_SCHOOLS } from "@/types/profile";
+import { ALL_PRESET_TAGS } from "@/types/interests";
+
+const DISCORD_API_BASE = "https://discord.com/api/v10";
+
+// "学部1年" / "修士2年" / "博士3年" などの学年文字列にマッチ
+const YEAR_ROLE_PATTERN = /^(学部|修士|博士)[1-9]\d*年$/;
+
+const RESIGNED_ROLE_NAME = "退会者";
+
+// 管理対象ロール判定（削除候補になりうるロール）
+// 付与はしないが過去に付与した興味分野・種別ロールも削除できるよう全種類を含む
+function isProfileValueName(name: string): boolean {
+  return (
+    name === RESIGNED_ROLE_NAME ||
+    (MEMBER_TYPES as readonly string[]).includes(name) ||
+    (FACULTIES as readonly string[]).includes(name) ||
+    (GRADUATE_SCHOOLS as readonly string[]).includes(name) ||
+    ALL_PRESET_TAGS.has(name) ||
+    YEAR_ROLE_PATTERN.test(name)
+  );
+}
+
+export type SyncRolesResult = {
+  added: string[];
+  removed: string[];
+  errors: string[];
+};
+
+export type MemberRoleParams = {
+  year?: string;
+  faculty?: string;
+  memberType?: string;
+  optedOut?: boolean;
+};
+
+type DiscordRole = { id: string; name: string };
+type DiscordMember = { roles: string[] };
+
+function getGuildAndToken(): { guildId: string; botToken: string } {
+  const guildId = process.env.DISCORD_GUILD_ID;
+  const botToken = process.env.DISCORD_BOT_TOKEN;
+  if (!guildId || !botToken) {
+    throw new Error("DISCORD_GUILD_ID または DISCORD_BOT_TOKEN が未設定です");
+  }
+  return { guildId, botToken };
+}
+
+export async function addGuildMemberRole(
+  userId: string,
+  roleId: string,
+): Promise<void> {
+  const { guildId, botToken } = getGuildAndToken();
+  const response = await fetch(
+    `${DISCORD_API_BASE}/guilds/${guildId}/members/${userId}/roles/${roleId}`,
+    {
+      method: "PUT",
+      headers: {
+        Authorization: `Bot ${botToken}`,
+        "Content-Type": "application/json",
+      },
+    },
+  );
+  if (!response.ok) {
+    const error = await response.text();
+    throw new Error(`ロール付与失敗: ${response.status} ${error}`);
+  }
+}
+
+export async function removeGuildMemberRole(
+  userId: string,
+  roleId: string,
+): Promise<void> {
+  const { guildId, botToken } = getGuildAndToken();
+  const response = await fetch(
+    `${DISCORD_API_BASE}/guilds/${guildId}/members/${userId}/roles/${roleId}`,
+    {
+      method: "DELETE",
+      headers: { Authorization: `Bot ${botToken}` },
+    },
+  );
+  if (!response.ok && response.status !== 404) {
+    const error = await response.text();
+    throw new Error(`ロール削除失敗: ${response.status} ${error}`);
+  }
+}
+
+async function fetchGuildRoles(): Promise<DiscordRole[]> {
+  const { guildId, botToken } = getGuildAndToken();
+  const response = await fetch(`${DISCORD_API_BASE}/guilds/${guildId}/roles`, {
+    headers: { Authorization: `Bot ${botToken}` },
+  });
+  if (!response.ok) {
+    const error = await response.text();
+    throw new Error(`ギルドロール取得失敗: ${response.status} ${error}`);
+  }
+  return response.json();
+}
+
+async function fetchGuildMemberRoles(userId: string): Promise<string[]> {
+  const { guildId, botToken } = getGuildAndToken();
+  const response = await fetch(
+    `${DISCORD_API_BASE}/guilds/${guildId}/members/${userId}`,
+    { headers: { Authorization: `Bot ${botToken}` } },
+  );
+  if (!response.ok) {
+    const error = await response.text();
+    throw new Error(`メンバー情報取得失敗: ${response.status} ${error}`);
+  }
+  const member: DiscordMember = await response.json();
+  return member.roles;
+}
+
+async function createGuildRole(name: string): Promise<DiscordRole> {
+  const { guildId, botToken } = getGuildAndToken();
+  const response = await fetch(`${DISCORD_API_BASE}/guilds/${guildId}/roles`, {
+    method: "POST",
+    headers: {
+      Authorization: `Bot ${botToken}`,
+      "Content-Type": "application/json",
+    },
+    body: JSON.stringify({ name }),
+  });
+  if (!response.ok) {
+    const error = await response.text();
+    throw new Error(`ロール作成失敗: ${response.status} ${error}`);
+  }
+  return response.json();
+}
+
+// ロール名 → ID のマップを返す。バッチ処理では一度だけ呼び出して使い回す。
+export async function getGuildRoleNameMap(): Promise<Map<string, string>> {
+  const roles = await fetchGuildRoles();
+  return new Map(roles.map((r) => [r.name, r.id]));
+}
+
+// マップにない名前のロールを Discord に作成してマップを更新する。
+export async function ensureRolesInMap(
+  names: string[],
+  roleNameMap: Map<string, string>,
+): Promise<void> {
+  const missing = [...new Set(names)].filter((n) => n && !roleNameMap.has(n));
+  for (const name of missing) {
+    try {
+      const role = await createGuildRole(name);
+      roleNameMap.set(role.name, role.id);
+      console.log(`[role-sync] ロール作成: "${role.name}" → ${role.id}`);
+    } catch (e) {
+      console.error(
+        `[role-sync] ロール作成失敗 "${name}": ${e instanceof Error ? e.message : String(e)}`,
+      );
+    }
+  }
+}
+
+// params から付与すべきロール ID 一覧を返す。
+// 退会者: 退会者ロールのみ
+// 卒業生: 卒業生ロールのみ
+// その他: その他ロールのみ
+// 学部生・院生: MEMBER_ROLE_ID + 学年 + 学部/学府
+function getTargetRoleIds(
+  params: MemberRoleParams,
+  roleNameMap: Map<string, string>,
+): { roleIds: string[]; matched: string[]; notFound: string[] } {
+  const matched: string[] = [];
+  const notFound: string[] = [];
+
+  const resolveByName = (name: string) => {
+    const id = roleNameMap.get(name);
+    if (id) {
+      matched.push(`"${name}"→${id}`);
+    } else {
+      notFound.push(`"${name}"`);
+    }
+    return id;
+  };
+
+  if (params.optedOut) {
+    const id = resolveByName(RESIGNED_ROLE_NAME);
+    return { roleIds: id ? [id] : [], matched, notFound };
+  }
+
+  if (params.memberType === "卒業生" || params.memberType === "その他") {
+    const id = resolveByName(params.memberType);
+    return { roleIds: id ? [id] : [], matched, notFound };
+  }
+
+  // 学部生・院生（memberType が未設定の場合も含む）
+  const roles: string[] = [];
+
+  const memberRoleId = process.env.MEMBER_ROLE_ID;
+  if (memberRoleId) {
+    roles.push(memberRoleId);
+    matched.push(`MEMBER_ROLE_ID(${memberRoleId})`);
+  }
+
+  for (const key of [params.year, params.faculty]) {
+    if (!key) continue;
+    const id = resolveByName(key);
+    if (id) roles.push(id);
+  }
+
+  return { roleIds: [...new Set(roles.filter(Boolean))], matched, notFound };
+}
+
+// params から ensureRolesInMap に渡すロール名一覧を返す。
+function getRoleNamesToEnsure(params: MemberRoleParams): string[] {
+  if (params.optedOut) return [RESIGNED_ROLE_NAME];
+  if (params.memberType === "卒業生" || params.memberType === "その他") {
+    return [params.memberType];
+  }
+  return [params.year, params.faculty].filter(Boolean) as string[];
+}
+
+export async function syncMemberDiscordRoles(
+  userId: string,
+  params: MemberRoleParams,
+  roleNameMap?: Map<string, string>,
+): Promise<SyncRolesResult> {
+  const map = roleNameMap ?? (await getGuildRoleNameMap());
+
+  await ensureRolesInMap(getRoleNamesToEnsure(params), map);
+
+  const {
+    roleIds: targetRoleIds,
+    matched,
+    notFound,
+  } = getTargetRoleIds(params, map);
+
+  // 現在のメンバーロールを取得して差分を計算
+  const currentRoleIds = await fetchGuildMemberRoles(userId);
+  const currentRoleSet = new Set(currentRoleIds);
+  const targetRoleSet = new Set(targetRoleIds);
+
+  // 管理対象ロール = プロフィール値名に対応するロールのみ（adminなど無関係なロールは触らない）
+  const managedRoleIds = new Set([
+    ...(process.env.MEMBER_ROLE_ID ? [process.env.MEMBER_ROLE_ID] : []),
+    ...[...map.entries()]
+      .filter(([name]) => isProfileValueName(name))
+      .map(([, id]) => id),
+  ]);
+
+  const toAdd = targetRoleIds.filter((id) => !currentRoleSet.has(id));
+  const toRemove = [...currentRoleSet].filter(
+    (id) => managedRoleIds.has(id) && !targetRoleSet.has(id),
+  );
+
+  console.log(
+    `[role-sync] ${userId} matched=[${matched.join(", ")}] notFound=[${notFound.join(", ")}] toAdd=[${toAdd.join(", ")}] toRemove=[${toRemove.join(", ")}]`,
+  );
+
+  const added: string[] = [];
+  const removed: string[] = [];
+  const errors: string[] = [];
+
+  for (const roleId of toAdd) {
+    try {
+      await addGuildMemberRole(userId, roleId);
+      added.push(roleId);
+    } catch (e) {
+      errors.push(
+        `add roleId=${roleId}: ${e instanceof Error ? e.message : String(e)}`,
+      );
+    }
+  }
+
+  for (const roleId of toRemove) {
+    try {
+      await removeGuildMemberRole(userId, roleId);
+      removed.push(roleId);
+    } catch (e) {
+      errors.push(
+        `remove roleId=${roleId}: ${e instanceof Error ? e.message : String(e)}`,
+      );
+    }
+  }
+
+  return { added, removed, errors };
+}