Sung-hyeon reunites with first love, Jin-hye at a class reunion.

I am a teacher! And you are a student! During school days, the first girl Daebeom fell in love with was a practice teacher. He hit on her daringly but she did nothing but treat him like a child. Grown up Daebeom always wants to see her again and one day he heard news that she will attend this alumni reunion. Daebeom decides to seduce her at the reunion. I should sleep with her!

Dongchul, who is managing a small bar, is always enthusiastic about his school reunions. One day, Yujin, who has never showed up to a reunion, shows up at his bar. Her baby face and vitality make her unlike other married women and all the men fall for her, especially Dongchul. They start a relationship but it abruptly flames out due to the sudden arrival of Dongchul’s wife. As they get to know each other's secrets, will their love be allowed to grow?