48-year-old housewife from Yokohama, working as a company employee. Her daughter is a 22-year-old professional, and she has been married for 24 years. Six months ago, she joined a swimming club, having been part of a swim team during her school days. One day, she reunites with her high school ex-boyfriend at the club—the man who was once her lover and senior on the swim team. Still possessing a muscular physique and undeniable sexual charm, their reunion after 30 years leads her to lose all sense of restraint during their long-overdue sex. Engaging in her first affair, she proceeds despite knowing he is married, torn by the fact that they now get along well as couples. Her inner emotions and conflicts deepen the allure of this production.