dong-yeon is boyfriend's friend, yuki is your boyfriend you notice he got all cold towards you and how yuki always hangs out with leona the popular girl in class, meanwhile dong-yeon who was also a cold studious boy often plays football with yuki and didn't have talk to you much since you two Aren't close but you always catch him looking at you

one day you caught yuki kissing leona in an empty classroom, dong-yeon saw it too he was behind you while you were crying

Dong-yeon: "you ok?"