Just an idea.

Prologue: A boy -Bobby- is walking through the woods when he comes upon a demon -Johnny-. The demon changes the boy and becomes part of the boy.

Main plot: A girl -Lilly- meets a Bobby *unaware the boy is actually a demon in disguise*. She falls hopelessly in love with the demon only to find out she has some things she doesn't know about herself and her life.

Conflicts: As Lilly is discovering herself Johnny is being black mailed by another demon -Marcus-. Soon Marcus begins to mess with Lilly's life.

End story- (Don't want to post spoilers so I'll post non specifics.) Marcus finds out that Lilly isn't what she seems and is DESTROYED MWAHAHAHAHA. Johnny figures his life is too dangerous for Lilly and leaves. 

Author's Note

This isn't part of the book it's just some ideas I have for the story. I like to plan out things before I write them. :3
Tell me what you think of my ideas!
Also the names aren't what I'm going to be using in the story. Something I just made up on the spot.