wait for the flashback again :) She's there.
She was mentioned one small time when hakyung went home and talk to yoonsung on the phone while he was with his friends playing pool. One of his friends was like “ohhh you talking to your girlfrieeeend what about (sisters name)” in a joking way.
HK got a little jealous heeehee. Flashbacks the next two ish chapters explaining her.
Aaa. Okay. I remember now. So if she knows Hk then does that mean yoonsung remembers? This story is killing me with all the suspense!!
Was she mentioned before?