diff --git a/src/iframe/life-game.js b/src/iframe/life-game.js
index f4860d4..48f5517 100644
--- a/src/iframe/life-game.js
+++ b/src/iframe/life-game.js
@@ -18,23 +18,24 @@ const cellSize = 600 / boardSize; //セルの大きさ(px)
 function isNextAlive(around, self) {
   // 自身が生きている & 周囲が 2 か 3 で生存
   if (self && 2 <= around && around <= 3) {
-    return true;
+    return self;
   }
   // 自身が死んでいる & 周囲が 3 で誕生
   if (!self && around === 3) {
-    return true;
+    return 1;
   }
-  return false;
+  return 0;
 }
 
 // cellの状態に応じた色を返す関数
 function getStyle(cell) {
-  // cellがtrueなら黒、falseなら白を返す
-  return cell ? "black" : "white";
+  if (cell === 0) return "white";
+  // cellの値に応じて色を返す場合はここに追加
+  return "black"; // デフォルトは黒
 }
 
 //Boardの初期化
-let board = Array.from({ length: boardSize }, () => Array.from({ length: boardSize }, () => false));
+let board = Array.from({ length: boardSize }, () => Array.from({ length: boardSize }, () => 0));
 const table = document.getElementById("game-board");
 
 //盤面をBoardに従って変更する関数達(Boardを変更したら実行する)
@@ -209,7 +210,7 @@ function progressBoard() {
       for (let ii = 0; ii < tate.length; ii++) {
         for (let jj = 0; jj < yoko.length; jj++) {
           if (tate[ii] !== 0 || yoko[jj] !== 0) {
-            around += board[i + tate[ii]][j + yoko[jj]] ? 1 : 0;
+            around += board[i + tate[ii]][j + yoko[jj]] !== 0 ? 1 : 0;
           }
         }
       }
diff --git a/src/lib/api/board.ts b/src/lib/api/board.ts
index f2b6969..9d62781 100644
--- a/src/lib/api/board.ts
+++ b/src/lib/api/board.ts
@@ -1,4 +1,4 @@
-export async function saveBoard(data: { board: boolean[][]; name: string }, isJapanese: boolean) {
+export async function saveBoard(data: { board: number[][]; name: string }, isJapanese: boolean) {
   try {
     const response = await fetch("/api/board", {
       method: "POST",
@@ -31,7 +31,7 @@ export type BoardListItem = {
   id: number;
   name: string;
   createdAt: string;
-  preview: boolean[][];
+  preview: number[][];
 };
 
 export async function fetchBoardList(isJapanese: boolean): Promise<BoardListItem[] | undefined> {
@@ -62,7 +62,7 @@ export async function fetchBoardList(isJapanese: boolean): Promise<BoardListItem
 export async function loadBoardById(
   id: number,
   isJapanese: boolean,
-): Promise<boolean[][] | undefined> {
+): Promise<number[][] | undefined> {
   try {
     const response = await fetch(`/api/board?id=${id}`);
 
@@ -76,7 +76,7 @@ export async function loadBoardById(
 
     const loadedBoard = await response.json();
 
-    return loadedBoard as boolean[][];
+    return loadedBoard as number[][];
   } catch (err) {
     console.error("Load error", err);
     if (isJapanese) {
diff --git a/src/lib/board-preview.ts b/src/lib/board-preview.ts
index 97ec012..b21dbe8 100644
--- a/src/lib/board-preview.ts
+++ b/src/lib/board-preview.ts
@@ -4,12 +4,12 @@ const PREVIEW_SIZE = 20;
  * 任意のサイズの盤面データから、中央 20x20 のプレビューを生成します。
  * 20x20 に満たない場合は、中央に配置し、周囲を false (空白) で埋めます。
  */
-export function createBoardPreview(boardData: boolean[][]): boolean[][] {
+export function createBoardPreview(boardData: number[][]): number[][] {
   const boardHeight = boardData.length;
   const boardWidth = boardData[0]?.length || 0;
 
-  const finalPreview: boolean[][] = Array.from({ length: PREVIEW_SIZE }, () =>
-    Array(PREVIEW_SIZE).fill(false),
+  const finalPreview: number[][] = Array.from({ length: PREVIEW_SIZE }, () =>
+    Array(PREVIEW_SIZE).fill(0),
   );
 
   const sourceStartRow = Math.max(0, Math.floor((boardHeight - PREVIEW_SIZE) / 2));
diff --git a/src/lib/models/BoardManager.svelte.ts b/src/lib/models/BoardManager.svelte.ts
index 8583b18..316feba 100644
--- a/src/lib/models/BoardManager.svelte.ts
+++ b/src/lib/models/BoardManager.svelte.ts
@@ -3,7 +3,7 @@ import { saveBoard, fetchBoardList, loadBoardById, type BoardListItem } from "$l
 
 type SaveState =
   | { saving: false }
-  | { saving: true; data: boolean[][]; name: string; preview: boolean[][] };
+  | { saving: true; data: number[][]; name: string; preview: number[][] };
 
 type LoadState =
   | { state: "closed" }
@@ -16,7 +16,7 @@ export class BoardManager {
 
   constructor() {}
 
-  openSaveModal(board: boolean[][]) {
+  openSaveModal(board: number[][]) {
     const preview = createBoardPreview(board);
     this.saveState = { saving: true, data: board, name: "", preview: preview };
   }
@@ -46,7 +46,7 @@ export class BoardManager {
     this.loadState = { state: "closed" };
   }
 
-  async load(id: number, isJapanese: boolean): Promise<boolean[][] | undefined> {
+  async load(id: number, isJapanese: boolean): Promise<number[][] | undefined> {
     this.closeLoadModal();
     return await loadBoardById(id, isJapanese);
   }
diff --git a/src/routes/+page.svelte b/src/routes/+page.svelte
index 9c53816..a3724e7 100644
--- a/src/routes/+page.svelte
+++ b/src/routes/+page.svelte
@@ -77,7 +77,7 @@
         break;
       }
       case "save_board": {
-        boardManager.openSaveModal(event.data.data as boolean[][]);
+        boardManager.openSaveModal(event.data.data as number[][]);
         break;
       }
       default: {
diff --git a/src/routes/api/board/+server.ts b/src/routes/api/board/+server.ts
index 2afaa69..ca696a2 100644
--- a/src/routes/api/board/+server.ts
+++ b/src/routes/api/board/+server.ts
@@ -4,7 +4,7 @@ import { createBoardPreview } from "@/lib/board-preview.js";
 import * as v from "valibot";
 
 const BoardSchema = v.object({
-  board: v.array(v.array(v.boolean())),
+  board: v.array(v.array(v.number())),
   name: v.pipe(v.string(), v.minLength(1, "盤面名は必須です。")),
 });