Ken-chan is always lonely and in tears because his mother is away working. When his crying grows louder, the kind housewife next door becomes concerned and comes to check on him. Ken-chan's desire to get closer to her deepens with each visit. She is a voluptuous, big-titted woman whose warmth and tenderness soothe his heart. As a teenager, Ken-chan's fantasies gradually expand, and he begins to see her as a romantic and sexual object. Seeking a way to invite her into his home, he devises one naughty prank after another. Eventually, their relationship crosses the line, evolving into something entirely new and intimate.