Arisa (Misaki Kanna), raised in a single-parent household with her mother, Michiko (Ayako Kano), lives with her alone. Her mother works at a supermarket during the day and at a snack bar at night to support their family. One day, her mother returns home drunk with a man. This is the first time Arisa has seen her mother like this, and the first time she has encountered this man... Soon, her mother remarries that man, Osamu Sakai, and an awkward life begins for the three of them. For Arisa, a teenager going through puberty, her stepfather's seemingly innocent actions stir deep within her awakening body. Despite her mind despising her stepfather, her body inexplicably craves the scent of a man... Eventually, Arisa learns to masturbate by smelling her stepfather's underwear and pillow. And her stepfather becomes aware of Arisa's actions...
