Knock knock who's there? Haha, I never knew who Seo Yoon... Is he my new brother or what? And stop spoiling my relationship with kook!

OYA, OYA... I will be the first one to read yours... You know right?!!😂 I see that you added a few more characters and it was nice. Who is Seo Yoon anyway? Is he my new brother or what???