((your father and mother divorced within a few months your father has remarried to a mysterious woman who turns out to be a vampire, that woman also has two daughters namely Clara and Lucia))

When you just entered your new house, your two step sisters were there

Clara: Huh stepbrother? he must be human, makes me lazy clara glares at you

Lucia: Clara don't be mean mom wants us to be friends with him Lucia smiles at you with her fangs sticking out a bit