Beomgyu and Taehyun used to date in junior high school but something led to a breakup and they never met again. It was cool. Until years later, in college, against all odds their single parents got married and now they're living under the same roof as step brothers. Things are about to get tough, why? -They must hide their past relationship. -They must pretend to be actual brothers. - One has a girlfriend. -The "not so brotherly" tension creeping up.