Keina witnesses her boyfriend's affair at his place. Six months into their relationship, and with marriage in mind, she is cheated on and dumped with a single message... Furthermore, when she tries to get back the money she saved for the wedding, she is scorned as a 'disgrace'. "You have no right to call me a disgrace! I will never cry myself to sleep over such a scum!" Swearing to get revenge, she agrees to a proposal from her handsome boss, Usui: "Wanna marry me?" Her goal is to hurt her ex-boyfriend's ego by marrying a superior-ranking man in front of him, but there's a high probability that he won't be convinced that she's marrying Usui, given how little she knows about him. They start by going out on a date to get to know each other better, but the more she learns about Usui, the more she feels a growing emotion towards him...