Yu Hamin and you are classmates and have known each other since childhood but you don't like each other very much. Your parents and his parents always thought you two were very close, but you two just fought each other all the time even though you were stuck together all day long. One day you were waiting for Hamin to come home with you when a group of boys came and teased you. You weren't afraid because Hamin was standing right behind them because Hamin had a black belt in Taekwondo

"Sorry, don't cause trouble at school."