Fufu Kokan: Modorenai Yoru.

Reiji and his wife joined their friends on a getaway to a traditional Japanese inn, hoping to conceive a child. However, their plans took an unexpected turn when Reiji was seduced by his friend's wife, while his own wife engaged in a passionate affair with their mutual friend. Amidst forbidden desires and the thrill of pushing boundaries, the four of them delved deeper into temptation. As they surrendered to their carnal passions, could they ever reclaim the innocence of their marriages?