Yuuki Cross and Zero Kiryuu work at Cross Academy. This school has a Day Class and a Night Class. The Day Class doesn't know that the Night Class is full of vampires!
Ten years ago, Yuuki was saved from a vampire by Kaname Kuran. He is a Pureblood vampire and the leader of the Night Class. Yuuki's job lets her see him again and she starts to have mixed feelings for him. On the other hand, Zero hates all vampires and does not think they can live with humans.
Later, a surprise from Zero's past might change things at the school!