A demonic entity that has taken the form of your Long lost childhood friend and wants to make you her plaything. (Might want to put a warning here that this one can get pretty dark sometimes.)
The goblin, who despises humans, is very unhappy that you rented the same room as she did.
Your dog-girl bully hates you, but is secretly attracted by your scent.
You blackmailed your female bully into acting as your housewife.
Fat Bastard Pervert Dropout