Vampire Knight

Vampire Knight is a shōjo manga and anime series written by Matsuri Hino. The series premiered in the January 2005 issue of LaLa magazine and is still on-going. Chapters are collected and published in collected volumes by Hakusensha, with nine volumes currently released in Japan. The manga series is licensed in English by Viz Media. The English adaptation premiered in the July 2006 issue of Viz's Shojo Beat magazine, with the collected volumes being published on a quarterly basis.

Yuki Cross's earliest memory is of a snowy night in winter, when she was attacked by an evil vampire and was saved by a kind one, Kaname Kuran. Yuki is the adopted daughter of the Headmaster of Cross Academy, Kaien Cross, who is an ex-vampire hunter that now wishes for vampires and humans to live alongside peacefully. She has grown up and become a prefect for the school which has one main purpose: for vampires to coexist peacefully with humans. Her fellow guardian and childhood companion, Zero Kiryu, whose parents were killed by a pure-blood vampire, is now determined to kill them all and refuses to trust them. Zero himself is now manifesting vampire traits, having been turned into a vampire after he was bitten by the vampire who attacked his family, Shizuka Hio, four years earlier.
Yuki tries to help him fight his bloodlust while also seeking to recover the memories she lost. As the series progresses, Zero's thirst for blood leads to his drinking from Yuki, by her consent, to avoid becoming a level E vampire and losing himself to his monstrous instincts. To stop this, Kaname gives Zero his own "pure" blood, even though the only way for an ex-human to become a truly "stabilized" vampire is to drink the blood of the one who bit them in the first place. However, since Kaname is a pure blood, his own blood helps keep Zero from going insane and from needing to feed from Yuki.
Eventually, it is revealed that Yuki is a pure blood vampire herself and the fiancee of Kaname. It is also revealed that Kaname is Yuki's elder brother and they spent their childhood together. Actually, Kaname is not Yuki's blood brother, but the ancient ancestor of the Kuran family resurrected by Rido Kuran. To save Yuki from being killed by Rido Kuran, their uncle, her mother had sealed her memories shortly before her own death and put Yuki under a spell so she could live as a human and avoid being found. After Yuki reawakens to her vampire nature, Rido again tries to kill her. As Kaname kills the corrupt vampire senate, Yuki fights Rido. During a fierce battle, Zero aids her in killing him, but later on tells her he will have to kill her when he sees her once again. She tells him that she will keep running, so that he will have a reason to live. Although this is where the anime ends, the manga continues the story and is updated monthly in LaLa Magazine.