Rika the Breeder

New boy Natsume Hiro comes to a boarding school unlike any other school in existence to solve/resolve something that happened in his past- but even that fact takes a while to emerge.
The school is a hotbed of bullying and rape kept slightly in check by a feudal organization called the Salon. The Salon protects its members from random abuse by specifying who can/must rape whom (yeah, there are must rapes here) under what circumstances, and punishing those who rape/abuse without proper permission. All this to be decided at the whim of the Salon head.
Sex at the school is both an overwhelming obsession, as befits an all-male society where there are no other outlets for stress, and a matter of down-and-dirty power politics, not unlike an American jail.
When you throw in the Byzantine institution of the Salon, you have a scenario reminiscent of the surrealistic, closed, hothouse world of British boys' schools. But the Rika world is even more bizarre than that.

This work has been left unfinished because the mangaka began to work on a non-bl title, called "Kousoku Angel Engine".