Sankaku Channel/kuro ai

Dark Love in english.

Plot Summary: A mansion with a young owner, turns to be just the face of an occult practice on this world. Young ladies are trained to serve well the desires of the man who can pay for it. Brutality and torture are just normal things to this family. Also debts from womans can be paid with just a single word of acceptance to render their bodies to the most barbaric practices. But in the end the excess can have a high cost.