Life as a teenage assasin

A young girl, brought up in an assasin clan is told that she is to be a wonted bried for many demon clan leaders. but she is never told why. The day on her 15 birthday she is assigned a mission, a mission to go to the human world and learn how to be normal the way she is to do that is to go to a human school. But what happens when she starts getting atact by demons at school and her assasin starts to show.