The devil i used to be

There are three types of people; humans, angels, and demons
In this world once you you grow up you will be one of the three
If you are a demon or a angel, you will get to see what kind of demon/angel you are
Tenshi has been told all her life by her parents that she will be a angel
But there's been rumors that one day one there might be demon that's a devil (the highest and most powerful kind of demon but there's never has been a devil in all of history)
But Tenshi is about is about to take one hell of a ride....