18+ Palladium Garden

After his grandfathers death our main character is invited at a high class school, which the grandfather was the director and owner of. The school is actually a place to train girls to be sex maids for high politician and rich people. the Main accepted the invitation, not to rule over all the girls, but rather to find his childhood friend who was said to be at the school. When he arrives he is told he must defeat 7 top girls (by taking them down and having sex with them) in order to be director, and hope to find any information on his childhood friend.

(Source: MU)