Fuufu Koukan: Modorenai Yoru (also known as Married Couple Swap: The Night of No Return
Note: The title in Japanese (夫婦交換もできない夜) translates roughly as “A Night When Even a Partner‑Swap Isn’t Possible.” The work is an adult‑oriented light‑novel/visual‑novel that falls into the erotic drama sub‑genre. Below is a comprehensive overview that covers the premise, main characters, plot beats, thematic concerns, style, and where you can legally locate the text. read fuufu koukan modorenai yoru link