My sister who has become fat recently and can't wear pants. He asks his younger brother for support, but his lascivious younger brother's mischief ignites, and he puts his hand in his sister's pants and moves his fingers. The younger brother who gradually escalate from here deceives his serious and naive sister, "Let's get irritated to get a small face" "Let's shake the hips in the cowgirl position to make a constriction" "Let's move to the missionary position to train the abdominal muscles" "Let's drink semen to make the skin smooth" and so on.