diff --git a/.changeset/chilly-cameras-lie.md b/.changeset/chilly-cameras-lie.md
new file mode 100644
index 00000000..bd4ce412
--- /dev/null
+++ b/.changeset/chilly-cameras-lie.md
@@ -0,0 +1,5 @@
+---
+"es-hangul": patch
+---
+
+feat: "이라/라" 케이스 추가
diff --git a/.changeset/old-mayflies-ring.md b/.changeset/old-mayflies-ring.md
new file mode 100644
index 00000000..aaf36791
--- /dev/null
+++ b/.changeset/old-mayflies-ring.md
@@ -0,0 +1,5 @@
+---
+'docs': patch
+---
+
+docs: 문서 배포 오류를 해결합니다.
diff --git a/docs/src/components/demo/choseong-includes-demo.tsx b/docs/src/components/demo/choseong-includes-demo.tsx
new file mode 100644
index 00000000..faaf8c8c
--- /dev/null
+++ b/docs/src/components/demo/choseong-includes-demo.tsx
@@ -0,0 +1,47 @@
+import React, { useState } from 'react';
+import { choseongIncludes } from 'es-hangul';
+
+export function ChoseongIncludesDemo() {
+  const [searchWord, setSearchWord] = useState<string>('홍길동');
+  const [userInput, setUserInput] = useState<string>('ㅎㄱㄷ');
+
+  const result = choseongIncludes(searchWord, userInput);
+
+  return (
+    <div className="bg-gray-200 dark:bg-gray-800 rounded-lg shadow-md p-6 max-w-md mx-auto my-8">
+      <div className="mb-4">
+        <label htmlFor="searchWord" className="block text-sm font-medium text-gray-700 dark:text-gray-300 mb-2">
+          Search Word
+        </label>
+        <input
+          id="searchWord"
+          type="text"
+          placeholder="Enter search word"
+          value={searchWord}
+          onChange={e => setSearchWord(e.target.value)}
+          className="w-full p-2 border border-gray-300 dark:border-gray-600 rounded-md focus:outline-none focus:ring-2 focus:ring-blue-500 dark:focus:ring-blue-300"
+        />
+      </div>
+      <div className="mb-4">
+        <label htmlFor="userInput" className="block text-sm font-medium text-gray-700 dark:text-gray-300 mb-2">
+          User Input
+        </label>
+        <input
+          id="userInput"
+          type="text"
+          placeholder="Enter user input"
+          value={userInput}
+          onChange={e => setUserInput(e.target.value)}
+          className="w-full p-2 border border-gray-300 dark:border-gray-600 rounded-md focus:outline-none focus:ring-2 focus:ring-blue-500 dark:focus:ring-blue-300"
+        />
+      </div>
+      {result !== null && (
+        <p
+          className={`mt-4 text-lg ${result ? 'text-green-500 dark:text-green-400' : 'text-red-500 dark:text-red-400'}`}
+        >
+          Result: {result ? 'Match found' : 'No match'}
+        </p>
+      )}
+    </div>
+  );
+}
diff --git a/src/josa.spec.ts b/src/josa.spec.ts
index 25e33b30..63f23969 100644
--- a/src/josa.spec.ts
+++ b/src/josa.spec.ts
@@ -41,6 +41,10 @@ describe('Hangul', () => {
       expect(josa('고기', '이랑/랑')).toBe('고기랑');
       expect(josa('과일', '이랑/랑')).toBe('과일이랑');
     });
+    it('주제의 보조사', () => {
+      expect(josa('의사', '이라/라')).toBe('의사라');
+      expect(josa('선생님', '이라/라')).toBe('선생님이라');
+    });
     it('서술격조사와 종결어미', () => {
       expect(josa('사과', '이에요/예요')).toBe('사과예요');
       expect(josa('책', '이에요/예요')).toBe('책이에요');
diff --git a/src/josa.ts b/src/josa.ts
index 54abdb6e..6fc5c007 100644
--- a/src/josa.ts
+++ b/src/josa.ts
@@ -14,7 +14,8 @@ type JosaOption =
   | '이에요/예요'
   | '으로서/로서'
   | '으로써/로써'
-  | '으로부터/로부터';
+  | '으로부터/로부터'
+  | '이라/라';
 
 const 로_조사: JosaOption[] = ['으로/로', '으로서/로서', '으로써/로써', '으로부터/로부터'];