Yuki Cross's earliest memory is of a snowy night in winter, when she was attacked by one vampire and was saved by another, Kaname Kuran.Yuki is the adopted daughter of the Headmaster of Cross Academy, Cross Kaien and has grown up and became a prefect for the school with one main purpose: to protect the Human Day Class Students and the Vampire Night Class Students from each other. Her fellow guardian, Zero Kiryu, a childhood companion whose parents were killed by a pureblood vampire, is now determined to kill them all and refuses to trust them. Through a cruel twist of fate, Zero becomes a vampire himself, having been bitten by a pure-blood vampire four years before, Shizuka Hio. Kaname leads the group of Night class as their President, with the help of Takuma Ichijo, the Vice-president.