Im Dayeon happened to witness the school's best insider, In Sahoon's (inevitable) break up scene.
After dealing with the embarrassment, Sahoon offers Dayeon a relationship contract in order to arouse the jealousy of his ex-girlfriend, Suzy. But even then, he got rejected.
Soon after, due to the accident of Dayeon's brother, she got forced to accept Sahoon's relationship contract.
Everyone's insider Sahoon and living in substinence outsider Dayeon got tangled in a polar opposite love affair as <Show Window Couple>.