Mako, a full-time housewife, is asked by a friend from her school days to look after their son, Shota, for a few days while her husband is away on a business trip. When she arrives at the meeting place, she sees Shota there. It turns out that Mako met Shota when he was a child. Reunited after several years, the two reminisce about old times, but Shota's heart starts beating fast when he sees Mako's enormous breasts. Unable to contain his desire, Shota suggests that they take a bath together. Seeing a naked woman for the first time arouses Shota, and Mako, noticing his gaze, begins to feel her body throbbing due to the absence of her husband and the recent lack of sex.