Natsuki and her husband move in with his father after the older man loses his wife. Natsuki is frustrated by a sexless marriage, while her lonely father-in-law is grieving the woman he loved. The moment they are alone while her husband is at work, restraint gives way: he pushes her down and fucks her without a condom, finishing inside. Their bodies fit so perfectly that desire explodes, and the two forget guilt and reason as they devour each other on instinct. Repeated creampies turn the forbidden affair into an obsession, and under the same roof they can no longer stop—even with pregnancy a possibility.