For me, the heart of the mix is in the sibling dynamic, which the school environment tests constantly. At home, they can have their weird vampire-human routine. At school, they have to perform as 'normal' siblings, which adds a layer of performative stress. The human might have to loudly make excuses for their sister's absence from a sunny courtyard, creating weird social friction. The comedy comes from their coded communication in public, the shared glances of panic during a fire drill (sunlight!), and the way they have to team up to solve school problems with a mix of human ingenuity and vampire abilities. It turns sibling solidarity into a survival strategy.