Kaibutsu Oujo S01E05 - Princess Blood

Reiri Kamura, a beautiful girl at the academy, approaches Hiro and later tells him to meet her on the school rooftop. There, she is revealed to be a vampire and sucks Hiro's blood, later turning him into her vampire slave. Using her werewolf instincts, Riza finds Reiri, who tells her that this is a ruse to gain access to the mansion and obtain Hime's powers by sucking her blood. Riza tries to stall Reiri for as long as she can, but to no use. Hiro returns to the mansion, but Hime weakens him with apotropaics. However, Hiro is later able to invite Reiri inside the mansion. Hime first is unable to land a blow on Reiri, but when Hime uses a wooden stake to startle Reiri, she lets Reiri off with a warning never to attack her again.