diff --git a/bokan.js b/bokan.js
new file mode 100644
index 0000000..4c1a37d
--- /dev/null
+++ b/bokan.js
@@ -0,0 +1,39 @@
+#!/usr/bin/env js
+
+(() => {
+    var timer = null, count = 5; msgArea = null;
+    function countdown() {
+	count --;
+	msgArea.innerText = `爆発まで あと${count}秒`;
+	if (count==0) {
+	    alert("ボカーーーンドンガラガッシャーン");
+	    msgArea.innerText = `正解は ${answer+1} だったよ!`;
+	} else {
+	    timer = setTimeout(countdown, 1000);  //1秒待つ
+	}
+    }
+    function stop() {
+	clearTimeout(timer);
+	document.body.style.background = "#00ff00";
+	msgArea.innerText = "世界は救われた";
+	msgArea.style.fontSize = "200%";
+	msgArea.style.fontWeight = "bold";
+    }
+    function init() {
+	let divs = document.querySelectorAll("div")
+	msgArea = document.getElementById("message");
+	if (divs.length == 0) {
+	    alert("divがないよ!"); return;
+	}
+	let answer = Math.floor(Math.random()*10)
+	console.log(`当たりは${answer+1}だよ`)
+	atari = divs[answer];
+	if (count>0) {
+	    atari.addEventListener("click", stop);
+	    timer = setTimeout(countdown, 1000);
+	}
+    };
+
+    document.addEventListener("DOMContentLoaded", init)
+})();
+