This is a fanfic I really like It's not mine it's by a guy named Waffles I'm just sharing it so you all can check it out

Naomi, a teenage girl who turns into a bully after being looked down by many. One day, she tries to bully a transfer student who is actually a demon masked as a human boy. The demon boy brings Naomi to the Demon world and makes her into his servant, as a punishment for dropping his pride as a demon. Or is it?