The Present Storyline

The Kuran family was targeted by the uncle Rido Kuran which looked to imprison the little princess Yuuki Kuran and make her his own and therefore achieve power. To protect her own child, Juri Kuran cast a spell on Yuuki and erased all her memories about being a vampire also caging the vampire-side of Yuuki somewhere in the recesses of her sub-conscious. Unfortunately, both Kuran parents died but Kaname, the young master, managed to seal away his uncle. Kuran's family request was to place Yuuki in the tutoring of Cross Kaien, a fearless and very powerful vampire hunter. This one has given up on his hunter name and decided to build up an Academy to unite the vampires and humans. Yuuki grew up knowing Cross was her foster-father but nothing about her old family. Her only aquaintance was Kaname, until someone appeared. Zero Kiryuu, was taken by Cross to the Academy, at the age of 10 due to the circumstances of a vampire attack. His family was killed by the vampire Shizuka Hio. Shizuka kidnapped his little brother Ichiru and left Zero a bite on the neck.
Time has passed: Zero knows everything about his past and hates vampires but he is on the edge of becoming one and Yuuki knows nothing but she is a vampire and is forcing the truth before herself. Kaname plans on returning his beloveds memories but is absolute about using Zero against his uncle who is awakening from his slumber.

Compliments to Floppy for All of the Above