Nagisa is transgender. She grew up in Hiroshima as a man, but now lives in Shinjuku, Tokyo as a woman. Due to an incident, she begins to live with middle school student Ichika, who is a distant relative. Ichika has been neglected by her mother Saori. From living in solitude by herself, to now living with Ichika, Nagisa develops maternal instincts for the first time.
