As a single man in his thirties, Shin-dong leads a mundane life in near-future Seoul. Tired of his lonely existence, he decides to rent out a room in his home to make some extra money. However, when a peculiar newlywed couple expresses interest in renting the bathroom, Shin-dong's life spirals into an unexpected journey of self-discovery and reflection on the meaning of family. He impulsively decides to accept them as renters, sparking a transformative journey that shifts his perspective on life, love, and the delicate balances that define home and family.