After two years with his girlfriend, they respect each other and have decent sexual chemistry, yet he still cannot commit to marriage. He suspects his buried sadism and fragile pride are holding him back. When he visits her home, her mother Kaori warmly welcomes him. While his girlfriend is away, he admits his doubts, and Kaori listens without judging. Her gentle acceptance somehow irritates him, and he turns all his pent-up frustration and sadistic urges on his girlfriend's mother.