Twincest

1-3) Aoya and Shion (22) are identical twins living with their older brother Kouhei (27) who is a salary man. Kouhei have had problems getting a girlfriend since the twins always got in the way since they want their brother to themselves.
4) Imai was dragged to a transvestite bar with his coworkers. He was forced to dress in drag and was teased by the other men but he was saved by a beautiful man who works there. It turns out that the one who saved him was an old sempai from high school.

Yuji and Kazuma are fraternal twins who are different from one another. Kazuma is the older brother but he is not as good at everything like Yuji. When they were in high school Kazuma noted that his feelings for Yuji was sexual. After entering university, Yuji and Kazuma became sex friends.

Towa is a omega with a large debt that he pays back by working part time jobs but he does not sell his body. One night while contemplating his life, Towa is approached by a beautiful man who wants to know how much a night will cost. The stranger is willing to pay him 200 000 for one night but it will be a threesome with the strangers twin brother (Aiji and Saiji) who call them self omegas. Anyway, after the deed the brother locked up Towa so that he wont find other customers.

Suu died and was brought back as a living corpse (Kyonshii) by his older twin brother, Xioyan. Suu has no memory of when he was alive but as months passed, he got used to being a living corpse with a job. It was later that Suu discovered his brother love for him and also his brothers sin.