Tsuma no Niku Ana ni Homestay Suru Macho Ryuugakusei ~Shucchouchuu no Sono Ura de, Tsuma wa Kurobikari Bou kara Afureru Hodo no Hakudaku o Sosogare, Yorokobi ni Michita Acme-gao o Sarashiteita~
Original title: 妻の肉穴にホームステイするマッチョ留学生 ～出張中のその裏で、妻は黒光り棒から溢れるほどの白濁を注がれ、悦びに満ちたアクメ顔を晒していた～
The Oosaki family has welcomed several homestay students and now, they are going to accept a long-term one. When the student comes however, it's a tall and muscular man. But in contrast with his scary appearance, he seems to be a polite and earnest person.
Suddenly, the husband is called to go on a business trip, leaving his wife, daughter and the young man alone at home. Meanwhile, the man's sexual urges gradually increase and then finally...