Rei is joking around and teasing her unpopular younger brother. He thinks she is really trying to seduce him, so he inserts his penis right after their parents leave the house. Rei climaxes with such force that she climaxes, but her brother, who is not used to women, ignores her and continues to thrust his hips desperately. Even after she climaxes, the pleasure of his thrusts continues, and she climaxes again and again, and despite her resistance, she continues to cum until her parents return home.