Vampires

(Warning spoilers) Matsuri Hino's vampires do not follow the traditional mythology of vampires; they are a spontaneous genetic oddity born from humans ten thousand years ago as a result of climate change, which gave rise to creatures who were sensitive to the sun, but immortal and do not age. The offspring of a union between these first vampires were known as Purebloods and any bite to a human from a Pureblood vampire would turn a human into a Level E vampire. The offspring between humans and vampires resulted in four levels of vampires, characterized by the amount of human blood. A Level A vampire has no human blood and a Level E being a former human; with levels B and C falling somewhere in between. Vampires drink blood, but it is not necessary to survive, and the blood of a Pureblood can grant them new powers. Along with their healing powers, vampires also have supernatural powers, the strength of their healing and powers corresponds to how pure their vampire blood is. Unlike a human pregnancy that takes roughly a year, a vampire pregnancy takes five years, and increases mother's thirst for blood; as result, any human friend a Pureblood may have cannot visit them during the duration of the pregnancy.