diff --git a/src/index.common.ts b/src/index.common.ts
index ff154ba..1141b43 100644
--- a/src/index.common.ts
+++ b/src/index.common.ts
@@ -14,7 +14,7 @@ export {
 
 export * from "./ranking-history.js";
 export * from "./params.js";
-export type { NarouParams } from "./narou.js";
+export type { ExecuteOptions, NarouParams } from "./narou.js";
 export * from "./narou-search-results.js";
 export type * from "./narou-ranking-results.js";
 export * from "./search-builder.js";
diff --git a/src/index.ts b/src/index.ts
index f298417..c4a829f 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -77,7 +77,7 @@ export async function rankingHistory(
   if (Array.isArray(result)) {
     return result.map(formatRankingHistory);
   } else {
-    throw new Error(result);
+    throw result;
   }
 }
 
diff --git a/src/narou-fetch.ts b/src/narou-fetch.ts
index 9c162b5..574a319 100644
--- a/src/narou-fetch.ts
+++ b/src/narou-fetch.ts
@@ -1,6 +1,6 @@
 import { unzipp } from "./util/unzipp.js";
 import NarouNovel from "./narou.js";
-import type { NarouParams } from "./narou.js";
+import type { ExecuteOptions, NarouParams } from "./narou.js";
 
 type Fetch = typeof fetch;
 
@@ -18,7 +18,8 @@ export default class NarouNovelFetch extends NarouNovel {
 
   protected async execute<T>(
     params: NarouParams,
-    endpoint: string
+    endpoint: string,
+    options?: ExecuteOptions
   ): Promise<T> {
     const query = { ...params, out: "json" };
 
@@ -36,7 +37,7 @@ export default class NarouNovelFetch extends NarouNovel {
       }
     });
 
-    const res = await (this.fetch ?? fetch)(url);
+    const res = await (this.fetch ?? fetch)(url, options?.fetchOptions);
 
     if (!query.gzip) {
       return (await res.json()) as T;
diff --git a/src/narou-jsonp.ts b/src/narou-jsonp.ts
index 8f4ad01..04666b2 100644
--- a/src/narou-jsonp.ts
+++ b/src/narou-jsonp.ts
@@ -1,5 +1,5 @@
 import NarouNovel from "./narou.js";
-import type { NarouParams } from "./narou.js";
+import type { ExecuteOptions, NarouParams } from "./narou.js";
 import { jsonp } from "./util/jsonp.js";
 
 /**
@@ -8,7 +8,8 @@ import { jsonp } from "./util/jsonp.js";
 export default class NarouNovelJsonp extends NarouNovel {
   protected async execute<T>(
     params: NarouParams,
-    endpoint: string
+    endpoint: string,
+    _options?: ExecuteOptions
   ): Promise<T> {
     const query = { ...params, out: "jsonp" };
     query.gzip = 0;
diff --git a/src/narou.ts b/src/narou.ts
index 5ff03ac..ac05b66 100644
--- a/src/narou.ts
+++ b/src/narou.ts
@@ -21,6 +21,10 @@ export type NarouParams =
   | RankingHistoryParams
   | UserSearchParams;
 
+export type ExecuteOptions = {
+  fetchOptions?: RequestInit;
+};
+
 /**
  * なろう小説APIへのリクエストを実行する
  * @class NarouNovel
@@ -35,7 +39,8 @@ export default abstract class NarouNovel {
    */
   protected abstract execute<T>(
     params: NarouParams,
-    endpoint: string
+    endpoint: string,
+    options?: ExecuteOptions
   ): Promise<T>;
 
   /**
@@ -46,9 +51,13 @@ export default abstract class NarouNovel {
    */
   protected async executeSearch<T extends keyof NarouSearchResult>(
     params: SearchParams,
-    endpoint = "https://api.syosetu.com/novelapi/api/"
+    endpoint = "https://api.syosetu.com/novelapi/api/",
+    options?: ExecuteOptions
   ): Promise<NarouSearchResults<NarouSearchResult, T>> {
-    return new NarouSearchResults(await this.execute(params, endpoint), params);
+    return new NarouSearchResults(
+      await this.execute(params, endpoint, options),
+      params
+    );
   }
 
   /**
@@ -58,11 +67,13 @@ export default abstract class NarouNovel {
    * @see https://dev.syosetu.com/man/api/
    */
   async executeNovel<T extends keyof NarouSearchResult>(
-    params: SearchParams
+    params: SearchParams,
+    options?: ExecuteOptions
   ): Promise<NarouSearchResults<NarouSearchResult, T>> {
     return await this.executeSearch(
       params,
-      "https://api.syosetu.com/novelapi/api/"
+      "https://api.syosetu.com/novelapi/api/",
+      options
     );
   }
 
@@ -73,11 +84,13 @@ export default abstract class NarouNovel {
    * @see https://dev.syosetu.com/xman/api/
    */
   async executeNovel18<T extends keyof NarouSearchResult>(
-    params: SearchParams
+    params: SearchParams,
+    options?: ExecuteOptions
   ): Promise<NarouSearchResults<NarouSearchResult, T>> {
     return await this.executeSearch(
       params,
-      "https://api.syosetu.com/novel18api/api/"
+      "https://api.syosetu.com/novel18api/api/",
+      options
     );
   }
 
@@ -87,8 +100,15 @@ export default abstract class NarouNovel {
    * @returns ランキング結果
    * @see https://dev.syosetu.com/man/rankapi/
    */
-  async executeRanking(params: RankingParams): Promise<NarouRankingResult[]> {
-    return await this.execute(params, "https://api.syosetu.com/rank/rankget/");
+  async executeRanking(
+    params: RankingParams,
+    options?: ExecuteOptions
+  ): Promise<NarouRankingResult[]> {
+    return await this.execute(
+      params,
+      "https://api.syosetu.com/rank/rankget/",
+      options
+    );
   }
 
   /**
@@ -98,9 +118,14 @@ export default abstract class NarouNovel {
    * @see https://dev.syosetu.com/man/rankinapi/
    */
   async executeRankingHistory(
-    params: RankingHistoryParams
+    params: RankingHistoryParams,
+    options?: ExecuteOptions
   ): Promise<RankingHistoryRawResult[]> {
-    return await this.execute(params, "https://api.syosetu.com/rank/rankin/");
+    return await this.execute(
+      params,
+      "https://api.syosetu.com/rank/rankin/",
+      options
+    );
   }
 
   /**
@@ -110,10 +135,15 @@ export default abstract class NarouNovel {
    * @see https://dev.syosetu.com/man/userapi/
    */
   async executeUserSearch<T extends keyof UserSearchResult>(
-    params: UserSearchParams
+    params: UserSearchParams,
+    options?: ExecuteOptions
   ): Promise<NarouSearchResults<UserSearchResult, T>> {
     return new NarouSearchResults<UserSearchResult, T>(
-      await this.execute(params, "https://api.syosetu.com/userapi/api/"),
+      await this.execute(
+        params,
+        "https://api.syosetu.com/userapi/api/",
+        options
+      ),
       params
     );
   }
diff --git a/src/ranking.ts b/src/ranking.ts
index 21ec693..5ae64f3 100644
--- a/src/ranking.ts
+++ b/src/ranking.ts
@@ -11,6 +11,7 @@ import {
   Fields,
 } from "./params.js";
 import type NarouNovel from "./narou.js";
+import type { ExecuteOptions } from "./narou.js";
 import type { SearchResultFields } from "./narou-search-results.js";
 import { addDays, formatDate } from "./util/date.js";
 
@@ -111,18 +112,18 @@ export default class RankingBuilder {
    * @returns {Promise<NarouRankingResult[]>} ランキング結果の配列
    * @see https://dev.syosetu.com/man/rankapi/#output
    */
-  execute(): Promise<NarouRankingResult[]> {
+  execute(options?: ExecuteOptions): Promise<NarouRankingResult[]> {
     const date = formatDate(this.date$);
     this.set({ rtype: `${date}-${this.type$}` });
-    return this.api.executeRanking(this.params as RankingParams);
+    return this.api.executeRanking(this.params as RankingParams, options);
   }
 
   /**
    * ランキングAPIを実行し、取得したNコードを元になろう小説APIで詳細情報を取得して結合します。
    */
-  async executeWithFields(): Promise<
-    RankingResult<DefaultSearchResultFields>[]
-  >;
+  async executeWithFields(
+    options?: ExecuteOptions
+  ): Promise<RankingResult<DefaultSearchResultFields>[]>;
   /**
    * ランキングAPIを実行し、取得したNコードを元になろう小説APIで詳細情報を取得して結合します。
    *
@@ -131,7 +132,8 @@ export default class RankingBuilder {
    * @returns {Promise<RankingResult<SearchResultFields<TFields>>[]>} 詳細情報を含むランキング結果の配列
    */
   async executeWithFields<TFields extends Fields>(
-    fields: TFields | TFields[]
+    fields: TFields | TFields[],
+    options?: ExecuteOptions
   ): Promise<RankingResult<SearchResultFields<TFields>>[]>;
   /**
    * ランキングAPIを実行し、取得したNコードを元になろう小説APIで詳細情報を取得して結合します。
@@ -141,7 +143,8 @@ export default class RankingBuilder {
    */
   async executeWithFields(
     fields: never[],
-    opt: OptionalFields | OptionalFields[]
+    opt: OptionalFields | OptionalFields[],
+    options?: ExecuteOptions
   ): Promise<RankingResult<DefaultSearchResultFields | "weekly_unique">[]>;
   /**
    * ランキングAPIを実行し、取得したNコードを元になろう小説APIで詳細情報を取得して結合します。
@@ -169,9 +172,10 @@ export default class RankingBuilder {
     TOpt extends OptionalFields | undefined = undefined
   >(
     fields: TFields | TFields[] = [],
-    opt?: TOpt
+    opt?: TOpt,
+    options?: ExecuteOptions
   ): Promise<RankingResult<SearchResultFields<TFields>>[]> {
-    const ranking = await this.execute();
+    const ranking = await this.execute(options);
     const fields$ = Array.isArray(fields)
       ? fields.length == 0
         ? []
@@ -186,7 +190,7 @@ export default class RankingBuilder {
     }
     builder.ncode(rankingNcodes);
     builder.limit(ranking.length);
-    const result = await builder.execute();
+    const result = await builder.execute(options);
 
     return ranking.map<
       RankingResult<
diff --git a/src/search-builder-r18.ts b/src/search-builder-r18.ts
index 02e961c..b2efd42 100644
--- a/src/search-builder-r18.ts
+++ b/src/search-builder-r18.ts
@@ -5,6 +5,7 @@ import type {
   SearchResultR18Fields,
   SearchResultOptionalFields,
 } from "./narou-search-results.js";
+import type { ExecuteOptions } from "./narou.js";
 import type {
   R18Site,
   SearchResultFieldNames,
@@ -30,8 +31,10 @@ export default class SearchBuilderR18<
    * @override
    * @returns {Promise<NarouSearchResults>} 検索結果
    */
-  execute(): Promise<NarouSearchResults<NarouSearchResult, T | TOpt>> {
-    return this.api.executeNovel18(this.params);
+  execute(
+    options?: ExecuteOptions
+  ): Promise<NarouSearchResults<NarouSearchResult, T | TOpt>> {
+    return this.api.executeNovel18(this.params, options);
   }
 
   /**
diff --git a/src/search-builder.ts b/src/search-builder.ts
index 30f871d..14f4e76 100644
--- a/src/search-builder.ts
+++ b/src/search-builder.ts
@@ -1,4 +1,5 @@
 import type NarouNovel from "./narou.js";
+import type { ExecuteOptions } from "./narou.js";
 import type {
   NarouSearchResult,
   SearchResultFields,
@@ -474,8 +475,10 @@ export abstract class NovelSearchBuilderBase<
    * なろう小説APIへの検索リクエストを実行する
    * @returns {Promise<NarouSearchResults>} 検索結果
    */
-  execute(): Promise<NarouSearchResults<NarouSearchResult, T>> {
-    return this.api.executeNovel(this.params);
+  execute(options?: ExecuteOptions): Promise<
+    NarouSearchResults<NarouSearchResult, T>
+  > {
+    return this.api.executeNovel(this.params, options);
   }
 }
 
diff --git a/src/user-search.ts b/src/user-search.ts
index eb607d9..36ad4f6 100644
--- a/src/user-search.ts
+++ b/src/user-search.ts
@@ -5,6 +5,7 @@ import type {
 } from "./narou-search-results.js";
 import type { UserFields, UserOrder, UserSearchParams } from "./params.js";
 import { SearchBuilderBase } from "./search-builder.js";
+import type { ExecuteOptions } from "./narou.js";
 
 /**
  * なろうユーザ検索API
@@ -104,7 +105,12 @@ export default class UserSearchBuilder<
    * なろう小説APIへのリクエストを実行する
    * @returns ランキング
    */
-  execute(): Promise<NarouSearchResults<UserSearchResult, TField>> {
-    return this.api.executeUserSearch(this.params as UserSearchParams);
+  execute(
+    options?: ExecuteOptions
+  ): Promise<NarouSearchResults<UserSearchResult, TField>> {
+    return this.api.executeUserSearch(
+      this.params as UserSearchParams,
+      options
+    );
   }
 }
diff --git a/test/narou-fetch.test.ts b/test/narou-fetch.test.ts
index f5578c4..5f6654f 100644
--- a/test/narou-fetch.test.ts
+++ b/test/narou-fetch.test.ts
@@ -95,6 +95,26 @@ describe('NarouNovelFetch', () => {
     expect(result).toEqual(mockData);
   });
 
+  it('should pass fetch options to fetch implementation', async () => {
+    const customFetchMock = vi.fn().mockResolvedValue({
+      json: vi.fn().mockResolvedValue(mockData)
+    });
+
+    const narouFetch = new NarouNovelFetch(customFetchMock);
+
+    // @ts-expect-error - Accessing protected method for testing
+    await narouFetch.execute(
+      { gzip: 0 },
+      'https://api.example.com',
+      { fetchOptions: { method: 'POST', headers: { 'X-Test': '1' } } }
+    );
+
+    expect(customFetchMock).toHaveBeenCalledWith(
+      new URL('https://api.example.com/?out=json'),
+      { method: 'POST', headers: { 'X-Test': '1' } }
+    );
+  });
+
   it('should set gzip to 5 when undefined', async () => {
     // URLパラメータをキャプチャするモック
     const requestSpy = vi.fn();