Azusa, to save her son Naoto from her husband's violence, seeks refuge at her sister Reiko's house. Although Reiko takes them in, she harbors sexual feelings towards Naoto. Meanwhile, Azusa is caught masturbating in the bath by Reiko's son Sho and ends up being assaulted. In the awkward atmosphere, they drink alcohol to liven things up but end up getting carried away. Even after their sons leave feeling uncomfortable, their arousal doesn't subside, leading them to head towards their sons' room.
