Kong Bo-Mi (Ahn Seo-Hyun) ia miserable that she has to share a room with her older sister Kong Eun-Joo (Lee Young-Ah). Even though her mom (Park Hae-Mi) promised to renovate the storage room into a bedroom for Kong Bo-Mi, she realizes she will be stuck with her older sister forever. Kong Bo-Mi then gets the idea that if she can get her older sister married, the bedroom will be all hers.