His wife Yuri has returned to her hometown to attend a local class reunion. Toru is alone at home for the first time in a long time and is looking to enjoy his freedom, when suddenly, his wife's sister Hitomi shows up at the house. Yuri has told Toru about her troubles, and Hitomi says she's there to give Toru a pep talk, but in reality, she's plotting to satisfy her own sexual desires. Toru is unaware of Hitomi's true purpose in her bold behavior, but...