During this summer vacation, Katsu, a nephew, visits his aunt's house for the first time in a long time. His uncle is away on a business trip, so he ends up spending the day alone with his kind aunt, whom he has admired for a long time. However, it seems that his aunt still thinks of Katsu as a child, as she starts watering the garden in light clothing, not caring about her gaze... Katsu can't help but stare at her braless breasts, which are transparent from the water splashes. For adolescent boys, the sight of her huge areolae is a strong stimulus, and he gets an erection. Then, for some reason, the aunt, seeing what was going on, suddenly takes her nephew's large, erect penis into her mouth and gently tells him, "Don't tell your mother."