diff --git a/package.json b/package.json
index c1add63..bd1a166 100644
--- a/package.json
+++ b/package.json
@@ -18,6 +18,7 @@
     "autobind-decorator": "2.4.0",
     "canvas": "2.6.1",
     "chalk": "4.1.0",
+    "emoji-regex": "9.0.0",
     "lokijs": "1.5.11",
     "mecab-async": "0.1.2",
     "misskey-reversi": "0.0.5",
diff --git a/src/index.ts b/src/index.ts
index 05f835b..7faa7cf 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -13,6 +13,7 @@ import BirthdayModule from './modules/birthday';
 import ReversiModule from './modules/reversi';
 import PingModule from './modules/ping';
 import EmojiModule from './modules/emoji';
+import EmojiReactModule from './modules/emoji-react';
 import FortuneModule from './modules/fortune';
 import GuessingGameModule from './modules/guessing-game';
 import KazutoriModule from './modules/kazutori';
@@ -57,6 +58,7 @@ promiseRetry(retry => {
 	// 藍起動
 	new 藍(account, [
 		new EmojiModule(),
+		new EmojiReactModule(),
 		new FortuneModule(),
 		new GuessingGameModule(),
 		new KazutoriModule(),
diff --git a/src/misskey/note.ts b/src/misskey/note.ts
new file mode 100644
index 0000000..0c1f718
--- /dev/null
+++ b/src/misskey/note.ts
@@ -0,0 +1,4 @@
+export type Note = {
+	id: string;
+	text: string | null;
+};
diff --git a/src/modules/emoji-react/index.ts b/src/modules/emoji-react/index.ts
new file mode 100644
index 0000000..8eba70a
--- /dev/null
+++ b/src/modules/emoji-react/index.ts
@@ -0,0 +1,57 @@
+import autobind from 'autobind-decorator';
+const emojiRegex = require('emoji-regex');
+
+import { Note } from '../../misskey/note';
+import Module from '../../module';
+import Stream from '../../stream';
+
+export default class extends Module {
+	public readonly name = 'emoji-react';
+
+	private htl: ReturnType<Stream['useSharedConnection']>;
+
+	@autobind
+	public install() {
+		this.htl = this.ai.connection.useSharedConnection('homeTimeline');
+		this.htl.on('note', this.onNote);
+
+		return {};
+	}
+
+	@autobind
+	private async onNote(note: Note) {
+		if (note.text == null) return;
+
+		const customEmojis = note.text.match(/:([^\n:]+?):/g);
+		if (customEmojis) {
+			// カスタム絵文字が複数種類ある場合はキャンセル
+			if (!customEmojis.every((val, i, arr) => val === arr[0])) return;
+
+			this.log(`Custom emoji detected - ${customEmojis[0]}`);
+
+			setTimeout(() => {
+				this.ai.api('notes/reactions/create', {
+					noteId: note.id,
+					reaction: customEmojis[0]
+				});
+			}, 2000);
+			return;
+		}
+
+		const emojis = note.text.match(emojiRegex());
+		if (emojis) {
+			// 絵文字が複数種類ある場合はキャンセル
+			if (!emojis.every((val, i, arr) => val === arr[0])) return;
+
+			this.log(`Emoji detected - ${emojis[0]}`);
+
+			setTimeout(() => {
+				this.ai.api('notes/reactions/create', {
+					noteId: note.id,
+					reaction: emojis[0]
+				});
+			}, 2000);
+			return;
+		}
+	}
+}
diff --git a/tsconfig.json b/tsconfig.json
index b070af7..07dbb1a 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -5,6 +5,7 @@
 		"noImplicitReturns": true,
 		"noImplicitThis": true,
 		"noFallthroughCasesInSwitch": true,
+		"strictNullChecks": false,
 		"experimentalDecorators": true,
 		"sourceMap": false,
 		"target": "es2017",