Nanoha Mizuno married a man significantly older than her, a choice she made despite her parents' objections due to the age gap—her husband is even older than her father. Having always been attracted to older men, she didn't let criticism stop her from marrying him. However, over time, the age difference has created growing friction in their daily lives, especially in their sex life. Though Nanoha is still at an age where she desires and enjoys active sex, her husband struggles to keep up. Despite her frequent advances, he often loses his erection before finishing, leaving her sexually unfulfilled. Frustrated and increasingly dissatisfied, she began watching adult videos to satisfy her desires. Eventually, she became intrigued by the actresses in those videos and started seeking new sexual experiences beyond her marriage.