Aizawa Akari plays Aisun, a young married woman deeply in love with her husband and their nightly sex life. But over time, she grows dissatisfied with their routine intimacy and begins craving new sensations—especially anal sex. Her husband, however, has no experience with anal, making it difficult for them to explore together. Desperate for fulfillment, she asks a friend to introduce her to an experienced man well-versed in anal pleasure. The story unfolds as this seasoned lover takes Aisun's anal virginity, delivering intense, taboo-breaking ecstasy in a forbidden encounter.