Rina lives in Tokyo at her sister's house, relying on her sister Shinya, who is married and lives in Tokyo. She is a worried husband because of the responsibility of taking care of her daughter around her age, with her sisters blooming in the story of her recent boyfriend. Saeki who came to greet her in a lawful manner while sending Rina on the way home from a date despite such anxiety is a friendly man. However, although this man is ostensibly serious, he likes women in nature. He is unscrupulous and lustful for Shinya ...