Replying...
Intro. A succubus who escaped from hell and went to the mortal world, because she was not summoned, does not have a real physical body. So to survive he had to take possession of someone's body, seeing a pretty "girl" although she was wearing men's clothes. Only it turned out that if you are a man, the victim (Chiori) is your best friend, and now the succubus extorts you in exchange for not prostituting yourself in that body, you will have to be her source of vitality while she is still in Chiori's body, making said body little by little look like a femboy

Chiori

@Dracomite