Mejoku no Anaume -Gakuen Houfuku Sensou- by Kokuchou - Adult Sex Game

The setting is a boarding school deep hidden in the mountainside completely isolated from the rest of civilization.
As this school follows a policy to treat scholarship students much more favourably than their average students, a considerable rift has formed between these two groups.
Inside the school, a student who got brutally raped and who was left in a horrific state is being discovered.
A group of ordinary students come to the conclusion that it must have been the scholarship students who had committed the crime and set out in retaliation to punish in the same manner and make one member of the opposing group experience the same fate.
Those two brutal incidents cause the already damaged relationship between those two groups to spiral down even further.
Teachers also mingle into this conflict and with this cycle of "an eye for an eye" it's the outset of a gruesome world.