Rina relies on her older sister, Maya, who is married and lives in Tokyo, and lives at her sister's couple's house. - A husband who can't help but worry about his sister who blooms in the story of her recently made boyfriend, and the responsibility of taking care of her daughter at her age. Despite such worries, while sending Rina on the way home from a date, Saiki who dutifully came to greet him was a friendly man. However, this man is ostensibly serious, but he really likes women. - Lust for Maya without sobriety ...