The last winter of his high school life. Kazuhara feels lost, facing the entrance and graduation exams. He's told to become independent and live alone. He tries to find a room, but doesn't receive many offers. Seeing him in this situation, his childhood friend, Takanashi Shiori, suggests he live with her. He thinks to himself that he was told to live alone, but after getting his parents' consent, he ends up living with his childhood friend. With that, their month-long cohabitation begins. He's sure nothing will happen since they've known each other for a long time. But, as they begin to live together, he begins to see her more and more as a woman...