On a snowy night ten years ago, Yuki was rescued from a fierce vampire by another vampire. For Yuki, that was the time when her memories begin...
Cross Academy has two types of classes — the Day Class and the Night Class. Unknown to people, the latter is composed of young, noble vampires. Yuki grows up as a prefect or "guardian" that helps in protecting the Day Class from the Night Class at the same time keeping the secret of the Night Class' existence.
A series of unexpected events arise, bringing up Yuki in a constant attachment with the vampires. She learns that the other prefect has been a vampire all along and memories of the past soon haunt her as she tries to uncover it, beyond all the romance, secrets, and lies.
Yuki is the foster daughter of the chairman of Cross Academy. She is a selfless person who's been in love with her savior right from the start. As a school prefect, it's one of her tasks to guard the gate and get the screaming fans out of the way as the Night Class members enter. Yuki performs very badly when it comes to academic stuff.
Yuki's blood is tempting for many vampires but there is only one who is successfully able to drink some of it. In fact, it is done without any form of struggle, as Yuki enthusiastically offers it herself.
Kaname is the feared leader of the Night Class. He has a reputation for being a pureblood and a descendant of the Kuran family — the family who became leaders when the race of vampires grew beyond control. Despite this, Kaname doesn't want to be treated differently. He is a gentle and calm vampire that cares for things very much. Like most of the students from his class, Kaname is popular among the Day Class girls.
Kaname's rescue of Yuki was not a coincidence. He considers her as the most important person in the world and he holds the key to where Yuki's past lies...
Zero is Yuki's ally as a prefect in guarding the school grounds at night from Day Class students trying to sneak in the Night Class to take photos and such. He appears hostile and his mere presence is enough to drive the Day Class fangirls away. Zero comes from a family of Vampire Hunters.
Four years before, Zero's family — his parents and twin brother — was brutally killed by a pureblood vampire. He miraculously survived and was taken into Cross Academy's custody, like Yuki. He was bitten by his family's assailant, causing him to become a low-class vampire.
Kaien is Yuki and Zero's foster parent and is the Chairman of Cross Academy. He treats the two like his real offpsring yet Yuki hardly calls him "Daddy" and Zero goes mad everytime being called "son." Normally, you would think of Kaien as ridiculous.
Considered as history's strongest legendary vampire hunter, Kaien used to kill. He set up the Night Class to focus on teaching young vampires because he firmly believes in pacifism that one day the strife between humans and vampires will come to an end and peace between the two will be achieved.