Masao, a nephew, visits the house of his remarried uncle. The uncle and Masao are excited to be able to spend a long time together, but Masao's eyes are glued to his new wife Mio, who is beautiful and hardworking and the talk of the relatives. As she cleans, Mio's tight-fitting pants emphasize her buttocks, and you can see her panty line faintly through them... and there is a dark stain along the crack of her buttocks... Unable to contain his excitement at this unexpected event, Masao can't help but get aroused, so he sneaks out of his uncle's sight and jumps on her buttocks!