Joy has one more mission to complete before she could graduate from 'Cupid High' as a 'college student' cupid.  She has to make Mark, the arrogant kingka of SM & JYPE High and her crush, to fall in love with the school

Sung Jong broke up with Yoon Ji when the pair was in high school, just because he was tired of her. Yoon Ji hated him for that and sworn to never forgive him. The two met again as adults when Sung Jong, who is now a C.E.O, was put in an arranged marriage with her as per his parents request in strengthening their business in car-manufacturing.

Mark finally have the courage to ask Lee Hae Jin, the girl of his dreams. Walking her back from home to school, Mark and Hae Jin can't help but to be excited. Flustered about how he should approach his girlfriend, Mark tried his best to resist himself from doing a single skinship with her. Can he hold for long?