Zero Kiryu

Zero Kiryu (錐生 ゼロ, Kiryū Zero) is one of the main characters of Vampire Knight. Zero is Yuki's childhood friend and the only other Cross Academy Guardian. Zero carries an anti-vampire gun named "Bloody Rose". Zero is the only Vampire Hunter/vampire who appears in the story.

Character outline
Even before becoming a vampire, Zero Kiryu was noted to be a talented vampire hunter due to being the stronger of a pair of rare twin hunters, his twin Ichiru. Zero bears a tattoo, the school insignia, on the left side of his neck originally used to suppress his vampire side, later used to tame him. Zero is a casual dresser, usually wearing school uniform incorrectly with the vest and red tie exposed from under his black jacket and wears three silver earings on his right ear(top)and 2 on his left (bottom). Zero was born in the year of the Dog and is 181cm (5'11) in height and his blood type is A.His favorite subject is social studies.

Personality
As a child, Zero was a quiet and gentle boy, to the point where Ichiru questioned whether he was even capable of being a vampire hunter. However after Shizuka's attack, Zero developed a strong distrust of vampires. Zero is a tsundere character, he sports a scary aura that makes most of the Day Class students wary of him. However, his innate nature is to protect humans, his cold attitude towards those he loves is likely to push them away and keep everyone at a distance.

Following his full awakening into a vampire, Zero harbors a great disgust towards himself because of inability to control his hunger and reliance on Yuki. His dismal outlook on his future and fear of what he might do causes him to give up and he almost kills himself with his own anti-vampire gun, Bloody Rose. He fights to ignore his hunger to the point of starvation rather than go to Yuki. He tries to help Yuki resolve her own problems and then impresses upon her that its alright for her to burden and use him because she owns him.

Zero is very hostile to the Night Class vampires when they threaten him, however he adopts his standard tsundere attitude when engaging them one on one while retaining a level of politeness. Zero expresses a great deal of anger toward Purebloods because of their mechanisms in his life in particular, he extends this hostility toward Yuki as well after she turns into a Pureblood vampire. In spite of this, his sense of duty override his issues ensuring his reliability and trustworthiness.

Background
Zero was born in a vampire hunter's family and had a identical twin brother named Ichiru. They, along with Kaito Takamiya, were trained as vampire hunters by Toga Yagari. Kaien later comments that they share a similar line of thinking thanks to this. Yagari lost an eye protecting Zero, when the still naive Zero makes himself vulnerable to ex-human vampire when the nurse turned wild and tried attacking Zero due to her Level E state. This was Zero's first lesson on the danger of seemingly innocent vampires.

Ichiru and Zero were once very close. Due to Ichiru's frail body, he could not keep up with training and lacked essential hunter skills. Ichiru constantly got sick, causing Zero to feel guilty about sharing their mother's love. One day Zero and Ichiru were taking a walk and Ichiru saw a woman sitting in a tree. Ichiru was in awe of how pretty she was, but Zero told Ichiru that it was a vampire and to stay away from her. A few days later, Ichiru ran off and Zero sensed the approach of the Pureblood vampire and ran to confront her. That vampire took Zero and bit him, hence turning him into a vampire. His parents came out in an attempt to save Zero but were killed. Zero at the time also believed his brother was killed.

After that attack Zero was taken in by Kaien Cross, the headmaster of Cross academy. His temperament turned cold and hostile, and at times cruel to the young Yuki who reached out to him. Her gentleness won him over, but Zero kept his affection for her to himself due to her loving Kaname, a vampire. However, Zero failed to reveal that he was going to turn into a vampire after Yuki revealed she was afraid of all other vampires. Over the next four years, the two became friends. Zero became her constant protector while Yuki mothered him, and acted as an older sister, though she is younger.

Plot Overview

 * Main Article: Plot Summary for Zero Kiryu

Ichiru Kiryu

 * See Also: Zero &amp; Ichiru

Ichiru is Zero's twin brother. In Zero's childhood, he and Ichiru have been very close siblings. It all came to a halt when Ichiru spotted Shizuka, a Pureblood who thought the Kiryu family killed her human lover. Worse news came to Ichiru when he heard his parents preferred Zero over him. When Shizuka slaughtered their parents, Zero instantly told Ichiru to run away, showing how much he cared for his twin. Soon after that, Zero went on to be with the Cross family: Kaien and Yuuki at the age of twelve years old. When Zero was locked up by the Vampire Hunter Association, Ichiru visits him and appears to have shot him due to hatred. However, it is revealed that Ichiru was terribly wounded because he tried to kill Rido, the person he was truly after because of his role in Shizuka's death. After he shoots his brother, he convinces Zero to drink his blood so they could finally become one as they were originally supposed to be. Ichiru stated that he was happy that he was not dead in Zero's heart and when they hug, he says that he feels comfortable to be in his arms, recalling a time when the brother's slept in the same bed often and were loved equally by their mother. After Ichiru's death, Zero appeared to grow vines, most likely from all of Shizuka Hio's blood that Ichiru has ingested to prevent his illness.

Yuki Cross

 * See Also: Yuki & Zero

Zero and Yuki have a very close relationship with one another. Having to live with her and Kaien when his parents were killed, Yuki has been the comforting and maternal caretaker of his. Soon, he grew to love her and even supported her relationship with Kaname. Zero feels extreme guilt when he bites Yuki, saying that he hates himself for doing it. After Yuki is finally revealed that she is a Pureblood and sister of Kaname, he broke ties with her and his hate to Purebloods is the visible emotion he shows to Yuki. It is unknown about his true feelings towards Yuki, though he is often shown being very protective of her.

Shizuka Hio
Shizuka was Zero's Pureblood master when he was bitten by her when he was a child. She taunts and teases, when she comes to the Academy with Ichiru, about her being Zero's Master. He despises her for all she did; killing his parents and took his brother away as well as his own human self.

Triva

 * Zero's first name is the kanji for rei, meaning "zero." In his last name, Kiryu, the ki means "auger" or "drill," and the ryu means "life."