Following the tragic suicide of his wife and child, Sasaki left his job and began a quiet life dedicated to painting. He unexpectedly reconnects with a former colleague and joins him at the house of his colleague's wife, Sachiko, who has been expecting him. It is revealed that Sasaki and Sachiko have secretly been having an affair for some time. That day, they engage in a sexual encounter while their colleague sleeps. Subsequently, Sasaki also begins a physical relationship with Sachiko's younger sister.