Dark Valentine (Monster High; Book 1 of the DV Duology)

Kieran Valentine has made many mistakes. All he wants to do is fix what he's broken, and to earn the trust of the other students at Monster High. Soon he crosses paths with Jackson Jekyll and Holt Hyde and he finally gets his wish.

But what happens when the three of them are faced with someone from Kieran's past?

Disclaimer: I DO NOT OWN MONSTER HIGH. I am merely a fan.