Chocolate Vampire: Kuroyurike no Himitsu

Synopsis

The human girl Chiyo and the vampire Setsu have made a blood pact as children, which binds them together. Having grown up in the meantime, the two attend a school where vampires and humans are taught together. Recently, rumors about a dangerous drug called "Spice" have been circulating there. This drug is supposed to improve the powers of the bloodsuckers so that everyone is crazy about it. As a member of the campus security force, Chiyo is in charge of the investigation. But suddenly, unknown persons kidnap Setsu's brother! Does the culprit have anything to do with the drug...?