Azusa evacuates to her older sister Reiko's house to save her son Naoto from her husband's violence. Reiko welcomes the two, but she harbors sexual feelings for Naoto. On the other hand, Azusa is attacked by Reiko's son Sho when she is indulging in masturbation in the bath because of her openness. In an awkward atmosphere, the two of them start to get confused after drinking alcohol to liven up the place. Even if the sons who became uncomfortable ran away, the hot flashes did not go away, and they turned their feet to the sons' room.
