Mafuyu Sone is caught petting a girl at school and is sent to live with her brother Takashi in Tokyo. Takashi's hospitality is sorely tested when the other girl, Sae Shirai, also shows up. Sae has been disowned by her parents and has nowhere else to go. Just as Takashi is finally getting used to the situation, feelings cool between Mafuyu and Sae. Decency forces Takashi to act like a big brother for the distraught Sae, but he discovers this means trouble for his own relationship with Mariko Abe.