diff --git a/src/search-builder.ts b/src/search-builder.ts
index 4e82a99..4f6c235 100644
--- a/src/search-builder.ts
+++ b/src/search-builder.ts
@@ -21,7 +21,7 @@ import type {
   DateParam,
 } from "./params.js";
 import { BooleanNumber, StopParam } from "./params.js";
-import type { Join } from "./util/type.js";
+import type { Join, RangeParam } from "./util/type.js";
 
 export type DefaultSearchResultFields = keyof Omit<
   NarouSearchResult,
@@ -54,6 +54,34 @@ export abstract class SearchBuilderBase<
     return Array.from(new Set(array));
   }
 
+  /**
+   * 範囲指定や配列をハイフン区切りの文字列に変換する
+   * @protected
+   * @static
+   * @param n 範囲指定オブジェクト、数値の配列、あるいは単一の数値
+   * @returns ハイフン区切りの文字列
+   */
+  protected static range2string<T extends number>(
+    n: T | readonly [T, T] | RangeParam<T>
+  ): Join<T | ""> | undefined {
+    if (typeof n === "object" && n !== null && !Array.isArray(n)) {
+      if ("equal" in n && typeof n.equal === "number") {
+        return n.equal.toString() as Join<T>;
+      } else if ("min" in n || "max" in n) {
+        const obj = n as Extract<RangeParam<T>, { min?: T, max?: T }>;
+        if (obj.min === undefined && obj.max === undefined) {
+          return undefined;
+        }
+        return `${obj.min ?? ""}-${obj.max ?? ""}` as Join<T | "">;
+      }
+      return undefined;
+    }
+    if (Array.isArray(n) && n.length > 2) {
+      throw new Error("範囲指定の配列は要素数を2つ以内にする必要があります");
+    }
+    return SearchBuilderBase.array2string(n) as Join<T>;
+  }
+
   /**
    * 配列をハイフン区切りの文字列に変換する
    * @protected
@@ -294,11 +322,15 @@ export abstract class NovelSearchBuilderBase<
   /**
    * 抽出する作品の文字数を指定します (length)。
    * 範囲指定する場合は、最小文字数と最大文字数をハイフン(-)記号で区切ってください。
-   * @param length 文字数、または[最小文字数, 最大文字数]
+   * オブジェクトによる指定 ({ min?: number, max?: number } または { equal: number }) も可能です。
+   * @param length 文字数、または[最小文字数, 最大文字数]、またはオブジェクト指定
    * @return {this}
    */
-  length(length: number | readonly number[]): this {
-    this.set({ length: NovelSearchBuilderBase.array2string(length) });
+  length(length: number | readonly [number, number] | RangeParam<number>): this {
+    const val = NovelSearchBuilderBase.range2string(length);
+    if (val !== undefined) {
+      this.set({ length: val });
+    }
     return this;
   }
 
@@ -315,8 +347,23 @@ export abstract class NovelSearchBuilderBase<
    * @return {this}
    */
   kaiwaritu(min: number, max: number): this;
+  /**
+   * 抽出する作品の会話率を%単位で範囲指定またはオブジェクトで指定します (kaiwaritu)。
+   * @param range 範囲指定オブジェクト
+   * @return {this}
+   */
+  kaiwaritu(range: RangeParam<number>): this;
 
-  kaiwaritu(min: number, max?: number): this {
+  kaiwaritu(minOrRange: number | RangeParam<number>, max?: number): this {
+    if (typeof minOrRange === "object" && minOrRange !== null) {
+      const val = NovelSearchBuilderBase.range2string(minOrRange);
+      if (val !== undefined) {
+        this.set({ kaiwaritu: val });
+      }
+      return this;
+    }
+
+    const min = minOrRange;
     let n: number | string;
     if (max != null) {
       n = `${min}-${max}`;
@@ -329,21 +376,29 @@ export abstract class NovelSearchBuilderBase<
 
   /**
    * 抽出する作品の挿絵数を指定します (sasie)。
-   * @param num 挿絵数、または[最小挿絵数, 最大挿絵数]
+   * オブジェクトによる指定 ({ min?: number, max?: number } または { equal: number }) も可能です。
+   * @param num 挿絵数、または[最小挿絵数, 最大挿絵数]、またはオブジェクト指定
    * @return {this}
    */
-  sasie(num: number | readonly number[]): this {
-    this.set({ sasie: NovelSearchBuilderBase.array2string(num) });
+  sasie(num: number | readonly [number, number] | RangeParam<number>): this {
+    const val = NovelSearchBuilderBase.range2string(num);
+    if (val !== undefined) {
+      this.set({ sasie: val });
+    }
     return this;
   }
 
   /**
    * 抽出する作品の予想読了時間を分単位で指定します (time)。
-   * @param num 読了時間(分)、または[最小読了時間, 最大読了時間]
+   * オブジェクトによる指定 ({ min?: number, max?: number } または { equal: number }) も可能です。
+   * @param num 読了時間(分)、または[最小読了時間, 最大読了時間]、またはオブジェクト指定
    * @return {this}
    */
-  time(num: number | readonly number[]): this {
-    this.set({ time: NovelSearchBuilderBase.array2string(num) });
+  time(num: number | readonly [number, number] | RangeParam<number>): this {
+    const val = NovelSearchBuilderBase.range2string(num);
+    if (val !== undefined) {
+      this.set({ time: val });
+    }
     return this;
   }
 
diff --git a/src/util/type.ts b/src/util/type.ts
index 851a5fd..4ff3405 100644
--- a/src/util/type.ts
+++ b/src/util/type.ts
@@ -24,3 +24,12 @@ type Stringable = string | number | bigint | boolean | null | undefined;
  * type JoinedNumbers = Join<Numbers>; // '1' | '2' | '3' | '1-1' | '1-2' | '1-3' | '2-1' | '2-2' | '2-3' | '3-1' | '3-2' | '3-3'
  */
 export type Join<T extends Stringable> = `${T}-${T}` | `${T}`;
+
+/**
+ * 範囲指定のためのオブジェクトの型。
+ * @template T - 範囲指定する値の型
+ */
+export type RangeParam<T extends number> =
+  | { min: T; max?: T }
+  | { min?: T; max: T }
+  | { equal: T };
diff --git a/test/search-builder.test.ts b/test/search-builder.test.ts
index 57a8deb..cd07d2b 100644
--- a/test/search-builder.test.ts
+++ b/test/search-builder.test.ts
@@ -787,6 +787,46 @@ describe("SearchBuilder", () => {
       expect(mockFn).toHaveBeenCalledTimes(1);
       expect(mockFn).toHaveBeenCalledWith(`0-${length}`, "5", "json", 3);
     });
+
+    test("if length = { min: 1000 }", async () => {
+      const mockFn = vi.fn();
+      setupMockHandler(mockFn, ["length", "gzip", "out"]);
+
+      const result = await NarouAPI.search().length({ min: 1000 }).execute();
+      expect(result.allcount).toBe(1);
+      expect(mockFn).toHaveBeenCalledTimes(1);
+      expect(mockFn).toHaveBeenCalledWith(`1000-`, "5", "json", 3);
+    });
+
+    test("if length = { max: 1000 }", async () => {
+      const mockFn = vi.fn();
+      setupMockHandler(mockFn, ["length", "gzip", "out"]);
+
+      const result = await NarouAPI.search().length({ max: 1000 }).execute();
+      expect(result.allcount).toBe(1);
+      expect(mockFn).toHaveBeenCalledTimes(1);
+      expect(mockFn).toHaveBeenCalledWith(`-1000`, "5", "json", 3);
+    });
+
+    test("if length = { min: 100, max: 1000 }", async () => {
+      const mockFn = vi.fn();
+      setupMockHandler(mockFn, ["length", "gzip", "out"]);
+
+      const result = await NarouAPI.search().length({ min: 100, max: 1000 }).execute();
+      expect(result.allcount).toBe(1);
+      expect(mockFn).toHaveBeenCalledTimes(1);
+      expect(mockFn).toHaveBeenCalledWith(`100-1000`, "5", "json", 3);
+    });
+
+    test("if length = { equal: 1000 }", async () => {
+      const mockFn = vi.fn();
+      setupMockHandler(mockFn, ["length", "gzip", "out"]);
+
+      const result = await NarouAPI.search().length({ equal: 1000 }).execute();
+      expect(result.allcount).toBe(1);
+      expect(mockFn).toHaveBeenCalledTimes(1);
+      expect(mockFn).toHaveBeenCalledWith(`1000`, "5", "json", 3);
+    });
   });
 
   describe("kaiwaritu", () => {
@@ -823,6 +863,26 @@ describe("SearchBuilder", () => {
       expect(mockFn).toHaveBeenCalledTimes(1);
       expect(mockFn).toHaveBeenCalledWith(`${min}-${max}`, "5", "json", 3);
     });
+
+    test("if kaiwaritu = { min: 10 }", async () => {
+      const mockFn = vi.fn();
+      setupMockHandler(mockFn, ["kaiwaritu", "gzip", "out"]);
+
+      const result = await NarouAPI.search().kaiwaritu({ min: 10 }).execute();
+      expect(result.allcount).toBe(1);
+      expect(mockFn).toHaveBeenCalledTimes(1);
+      expect(mockFn).toHaveBeenCalledWith(`10-`, "5", "json", 3);
+    });
+
+    test("if kaiwaritu = { max: 50 }", async () => {
+      const mockFn = vi.fn();
+      setupMockHandler(mockFn, ["kaiwaritu", "gzip", "out"]);
+
+      const result = await NarouAPI.search().kaiwaritu({ max: 50 }).execute();
+      expect(result.allcount).toBe(1);
+      expect(mockFn).toHaveBeenCalledTimes(1);
+      expect(mockFn).toHaveBeenCalledWith(`-50`, "5", "json", 3);
+    });
   });
 
   describe("sasie", () => {
@@ -859,6 +919,54 @@ describe("SearchBuilder", () => {
       expect(mockFn).toHaveBeenCalledTimes(1);
       expect(mockFn).toHaveBeenCalledWith(`${min}-${max}`, "5", "json", 3);
     });
+
+    test("if sasie = array > 2 length throws", async () => {
+      const builder = NarouAPI.search();
+      expect(() => {
+        // @ts-expect-error Testing invalid runtime input
+        builder.sasie([1, 2, 3]);
+      }).toThrow("範囲指定の配列は要素数を2つ以内にする必要があります");
+    });
+
+    test("if sasie = { min: 5 }", async () => {
+      const mockFn = vi.fn();
+      setupMockHandler(mockFn, ["sasie", "gzip", "out"]);
+
+      const result = await NarouAPI.search().sasie({ min: 5 }).execute();
+      expect(result.allcount).toBe(1);
+      expect(mockFn).toHaveBeenCalledTimes(1);
+      expect(mockFn).toHaveBeenCalledWith(`5-`, "5", "json", 3);
+    });
+
+    test("if sasie = { max: 10 }", async () => {
+      const mockFn = vi.fn();
+      setupMockHandler(mockFn, ["sasie", "gzip", "out"]);
+
+      const result = await NarouAPI.search().sasie({ max: 10 }).execute();
+      expect(result.allcount).toBe(1);
+      expect(mockFn).toHaveBeenCalledTimes(1);
+      expect(mockFn).toHaveBeenCalledWith(`-10`, "5", "json", 3);
+    });
+
+    test("if sasie = { min: 5, max: 10 }", async () => {
+      const mockFn = vi.fn();
+      setupMockHandler(mockFn, ["sasie", "gzip", "out"]);
+
+      const result = await NarouAPI.search().sasie({ min: 5, max: 10 }).execute();
+      expect(result.allcount).toBe(1);
+      expect(mockFn).toHaveBeenCalledTimes(1);
+      expect(mockFn).toHaveBeenCalledWith(`5-10`, "5", "json", 3);
+    });
+
+    test("if sasie = { equal: 5 }", async () => {
+      const mockFn = vi.fn();
+      setupMockHandler(mockFn, ["sasie", "gzip", "out"]);
+
+      const result = await NarouAPI.search().sasie({ equal: 5 }).execute();
+      expect(result.allcount).toBe(1);
+      expect(mockFn).toHaveBeenCalledTimes(1);
+      expect(mockFn).toHaveBeenCalledWith(`5`, "5", "json", 3);
+    });
   });
 
   describe("time", () => {
@@ -895,6 +1003,46 @@ describe("SearchBuilder", () => {
       expect(mockFn).toHaveBeenCalledTimes(1);
       expect(mockFn).toHaveBeenCalledWith(`${min}-${max}`, "5", "json", 3);
     });
+
+    test("if time = { min: 10, max: 20 }", async () => {
+      const mockFn = vi.fn();
+      setupMockHandler(mockFn, ["time", "gzip", "out"]);
+
+      const result = await NarouAPI.search().time({ min: 10, max: 20 }).execute();
+      expect(result.allcount).toBe(1);
+      expect(mockFn).toHaveBeenCalledTimes(1);
+      expect(mockFn).toHaveBeenCalledWith(`10-20`, "5", "json", 3);
+    });
+
+    test("if time = { min: 10 }", async () => {
+      const mockFn = vi.fn();
+      setupMockHandler(mockFn, ["time", "gzip", "out"]);
+
+      const result = await NarouAPI.search().time({ min: 10 }).execute();
+      expect(result.allcount).toBe(1);
+      expect(mockFn).toHaveBeenCalledTimes(1);
+      expect(mockFn).toHaveBeenCalledWith(`10-`, "5", "json", 3);
+    });
+
+    test("if time = { max: 20 }", async () => {
+      const mockFn = vi.fn();
+      setupMockHandler(mockFn, ["time", "gzip", "out"]);
+
+      const result = await NarouAPI.search().time({ max: 20 }).execute();
+      expect(result.allcount).toBe(1);
+      expect(mockFn).toHaveBeenCalledTimes(1);
+      expect(mockFn).toHaveBeenCalledWith(`-20`, "5", "json", 3);
+    });
+
+    test("if time = { equal: 10 }", async () => {
+      const mockFn = vi.fn();
+      setupMockHandler(mockFn, ["time", "gzip", "out"]);
+
+      const result = await NarouAPI.search().time({ equal: 10 }).execute();
+      expect(result.allcount).toBe(1);
+      expect(mockFn).toHaveBeenCalledTimes(1);
+      expect(mockFn).toHaveBeenCalledWith(`10`, "5", "json", 3);
+    });
   });
 
   describe("ncode", () => {