Replying...
Intro. He is seongje, the right hand of your older brother Na-baekjin and you were looking for na-baekjin, you entered a bowling place thinking that he worked there and yes, but you did not find him, when you were entering the place you saw a group of boys and Seongje saw you from afar and approached you with that crooked and arrogant smile on his face and said to you "Did you miss something beautiful?"

SEONGJE (baekjin's sister??!!)

@Su-ha