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 is an honest character with a strong affection for Yuki and a kind heart.

Appearance
Zero bears a tattoo, the Hunter's Seal, 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 left ear (top) and 2 on his right (bottom). His hair is a pale, silvery white, with impressively pale skin, and his eyes are pale purple or lavender coloured.

Personality
"Even if I loathe vampires...Even if I don't want to hurt anyone...I can't stop myself from lusting for blood."

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, he can also glare in a way that even Kaname Kuran calls it scary. 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. He also happens to be a stickler for details, as he doesn't consider himself as an adopted son of Kaien's family with Yuki, or holds all the details about how vampires and humans can be similar in their own ways. As told by Ichiru to Kaien, Zero's favorite food is vegetable soup.

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 hostile to the Night Class vampires when they threaten him, however he adopts his standard tsundere attitude when engaging them one on one retaining a level of civility. 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 overrides 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.

One day in winter, Zero and Ichiru were taking a walk and Ichiru saw a woman sitting in a tree. Ichiru was amazed at 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. She was a pureblood named Shizuka Hio, she took Zero and bit him, making him suffer the painful transformation into a vampire. His parents came out in an attempt to save Zero but were killed by Shizuka. 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. Yuki approached him carefully and after four years, her gentleness began to win 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, until the third night when Zero bit Yuki, revealing himself to be a vampire, though she still cared for him and proved to be a true friend. 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

 * Main article: Zero & Ichiru

Zero and his twin brother Ichiru have a complicated relationship right from the start. As Ichiru is often ill and unable to persist for long periods of time without a minor fever and or any other sickness, this causes Zero to worry over him endlessly. However, their relationship is very close, close to the point that Ichiru likes to share the same bed together with his brother when they sleep. One day, the pureblood vampire Hiou Shizuka attacks the Kiryuu family. She bites Zero and kills his parents in the process. This was found to be Ichiru overhearing a conversation their parents had of him and his weakness and angry, runs out and reaches an understanding with Shizuka. Slowly, Ichiru started to feel jealousy and hatred towards Zero. As the years pass by and Zero and Ichiru meet each other again in Cross Academy, their relationship does not improve much either and appears to worsen. Zero is still greatly hated by Ichiru and he gets angry often as Ichiru regards Shizuka as a 'god' and because of his younger brother's betrayal. This continues on for a long time until finally in one of the later parts of the series, Ichiru finds Zero suffering and falling into his Level E instincts and before dying, he asks Zero to drink his blood so that 'they can always be one'. This implies that their previous brotherly love has probably been restored.

Yuki Cross

 * Main article: Yuki & Zero

Yuki and Zero became childhood friends after he went to live with Kaien after the massacre by Shizuka on his family. When Yuki's true identity is revealed Zero seems to detatch himself from the feelings he has for Yuki, and claims he will kill her, but actually helps her after she was attacked by another pureblood, and was going to allow her to bite him. It also reveals that when Sayori "Yori" Wakaba talks to him about Yuki, he seems to think about her as well, with a depressed expression as if he seems to miss her as well.

Shizuka Hio
Shizuka became Zero's master after the pureblood bit him during her attack on his family. She claims she did it because she knew that Zero would challenge her and become strong. Shizuka meets Zero again 4 years later at Cross Academy in the guise of Maria Kurenai, but thanks to Yagari's warning, Zero recognises who she really is. She taunts him about her being Zero's Master and his being under her command. He despises her for all she did; killing his parents and took his brother away as well as his own human self. When Yuki bargains her humanity for Zero's life, Zero overcomes his master's commands and manages to wound her. Zero had every intention of sacrificing his life to kill Shizuka, but is prevented by Yuki and though the final kill was not his, he was blamed for it by the council and Ichiru.

Kaname Kuran

 * Main article: Kaname & Zero

Starting from their first encounter, the two have always had a difficult relationship, particularly in regards to Yuki. Neither man especially trusts the other, though both respect each other's willingness to protect and care for Yuki. Despite their mutual dislike, for the sake of Zero continuing to protect Yuki, Kaname offered Zero his blood to help prevent him from falling to Level E. Though they managed to maintain a level of tolerance for one another in the first arc, since the start of the second arc their relationship has deteriorated, with Zero even going so far as to consider Kaname as the worst of the purebloods due to the latter's actions against vampire society.

Powers
Zero is a highly talented vampire hunter and possesses the standard abilities to sense vampires from a great distance, accelerated healing and in spite of being a vampire, also able to wield anti-vampire weapons. Since he became a vampire, Zero is able to distinguish purebloods from other vampires and has gained improved healing abilities. Kuran Kaname explains that after he eats Ichiru he would become the world's strongest hunter. He, then, explains that he has the blood of Kuran Yuki because Yuki was a pureblood, Kaname and Shizuka was as well. After completing the fragment[1] Zero is able to transform the Bloody Rose into its evolved state[2], where is literally becomes a part of his body, however the cost is using a high amount of his blood[3].

Trivia
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."