Fuufu Koukan: Modorenai Yoru
English title: Married Couple Swap
Japanese title: 夫婦交歓 ~戻れない夜~
Type: ONA
Episodes: 8
Source: Manga
Genres: Hentai
Studios: Studio Hokiboshi
Producers: Suiseisha
Duration: 6 min per ep
Rating: Rx - Hentai

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?

(Source: Coolmic.me)