Plagerism: the practice of taking one's work or ideas and passing them off as one's own
It doesn't matter how you "shake things up", it's been done before. It doesn't matter what "secrets" they're hiding (she's a vampire, he's a werewolf, one of them is dying, etc.) it's boring and overused, just like you if you write that trash.
It was good the first three times I read it, but now there are three million different authors writing the same book.
It's dry, crusty plagerism.