Cross Academy has two isolated classes: the Day Class and Night Class, attended by top-notch students. Yuuki Cross and Zero Kiryuu are the academy's prefects, responsible for maintaining discipline amongst the students - especially during evening classes. But this is no easy task, as the Night Class is populated by stunningly beautiful aristocratic vampires. As guardians of both the Night Class' secrets and the safety of the Day Class, Yuuki and Zero are a stalwart defense. Yuuki is the adopted daughter of the academy's chairman and takes her role very seriously, approaching it with utmost dedication and enthusiasm. Not only does her job allow her to meet her rescuer and romantic interest, Kaname Kuran - the dorm president of the Night Class - but she is also driven to protect the academy's secrets. On the other hand, Zero's strong anti-vampire sentiments make him an effective enforcer, even taking things as far as killing them. The question remains: can humans and vampires coexist peacefully at Cross Academy, given its unusual setup? Only time will tell.