'Wooyoung is a popular guy. Along with Taecyeon, junho and Chansung he is actually the most popular guy in school. These guys likes making bets, and one day he is dared to ask the most unpopular girl in school out, and make her fall for him, just for the money and fun, of course.

'IU is a poor, unpopular girl who works two part time jobs, and lives in a two-rooms apartment along with her parents, and four siblings. She is the oldest one of them. Apart from that, she also has other kinds of trouble, like bullying, a weird geeky guy chasing her and her still undiscovered leukemia.
They say it’s just a harmless bet, but what will happen when a lot of people’s feelings are getting involved, and when someone risks dying?