Yuki Cross has no memory of her past prior to the moment she was saved from a vampire attack ten years ago. Her first memory is of a snowy day and a level E vampire appearing and attacking her and then another vampire named Kaname Kuran saved her. She was adopted by the headmaster of Cross Academy and she is now a first year student in the Day Class and also a member of the disciplinary committee. As a member of the disciplinary committee she works alongside with Zero to guard the Academy's secret. Yuki believes that vampires and humans can coexist peacefully. As she grew up, Yuki became fond of Kaname, but then Zero came along. After she started showing an interest in Zero instead of Kaname, Kaname got ticked off and made a deal with Headmaster Cross, Yuki's adopted father, to let him take care of her. In exchange, Kaname would Zero's life as miserable as possible.

Zero is a very unique vampire because he is also a vampire hunter. He despises other vampires, especially pure blooded vampires because they stole his humanity and murdered his family. That fact alone makes him a very bitter angry and insolent individual, to an extent that even looking into his eyes would scare most people except Yuki.

Kaname is usually calmly authoritative. That is unless Yuki is around. When Yuki is near he becomes gentle and kind. Despite how he treats Yuki, the Night Class vampires and even Yuki herself is confused about how he treats her. To everyone else he is very strict and imposes very harsh disciplinary actions as the dorm president.