Kaien Cross

Headmaster Kaien Cross (黒主理事長, Kurosu Kaien Rijicho) is a character in the manga and anime series, Vampire Knight by Matsuri Hino. In the story, he is both Headmaster of Cross Academy, and current head of the Vampire Hunters Association. He is also known as the strongest vampire hunter in history, and is quite the legend. He is the adoptive father of Yuki Cross, the heroine of the story. Kaien's role in the story is largely observant, and he takes little action until the hunter's association attacks the night class.

Appearance
Kaien has long straw coloured hair and usually pulls it back into a ponytail. Though he is over 200 years old, he looks to be in his mid twenties. Kaien enjoys wearing very odd clothing and can be spotted with oversized lion feet slippers and large colourful hats. Kaien is one of the few characters that wears spectacles, though he removes them in times of action.

Personality
Kaien sports a cheerful personality, yet can be serious at the same time. It can be said that he has a few odd personality quirks, such as his propensity to launch into tearful dramatics over the idea of being a poor parent to Yuki. Additionally, he enjoys ribbing his adopted children, particularly Zero, who refuses to consider Kaien and Yuki family, a fact which Kaien jokingly claims breaks his heart. Kaien also enjoys cooking very strange food and making Yuki and Zero try it. He is often mockingly sad if they don't enjoy it.

Kaien can also appear thoughtless, frequently overriding and ignoring Zero's distaste for vampires. He often tells only half truths to protect Zero and Yuki, and kept his knowledge of Yuki's past secret from both her and Zero. He is however quite proud, and very protective, of both his children.

Background
Kaien has not always been so happy go-lucky. At his prime as a Vampire Hunter, Kaien Cross was known as the "Vampire without Fangs" due to his strength and skill as a Vampire Hunter, and also the fact that he was born with an abnormally high amount of vampire genetic material compared to other Vampire Hunters. Thanks to his vampire DNA, Kaien is over 200 years old and no longer seems to age.

Kaien is friends with pureblood vampire, Isaya Shouto, and he also used to intentionally pick fights with him. With Juri's influence, Kaien took on Juri's dream, and retired as a vampire hunter rejoining the family business of running Cross Academy 16 years prior to the story's beginning. Following the deaths of Juri and Haruka Kuran, Kaien took in their hidden daughter, Yuki, after Kaname Kuran brought her to Cross for safekeeping. Cross kindly took Yuki in, and adopted her within the week. Thus becoming her very doting and slightly odd father, much to Yuki's annoyance. Kaien also took Zero Kiryu into his home several years later. He also wished to adopt Zero, but Zero refused.

Shortly after Zero's arrival, Kaien, with Kaname's assistance, was finally able to establish the Night Class to promote understanding between humans and vampires. Zero refused to attend high school, skips a year, but Kaien was able to convince him to attend the following year in order to prevent Yuki from being alone in the duties of being a guardian.

Plot Summary
Kaien has installed Yuki and Zero as the only guardians, and ignores Zero's request for assistance. When Zero completely awakens as a vampire, he performs the ceremony to have Yuki tame Zero.

Kaien accompanies Yuki and Zero to the Hunter's Association's main headquarters in order to look up the records on Yuki's history. He states that it is due to his worry about the effect on Zero. Shortly after, Yuki accidently uncovers the fact that Kaien was once a vampire hunter, though Kaien, ashamed for having killed vampires in the past, didn't want her to know. She states that he is her father and nothing has changed. Kaien is touched.

Kaien is fully aware of who Kaname is to Yuki, but he still questions Kaname's motives, when making Yuki his lover.

When Yagari returns, they go check on Zero following Yuki's change. Kaien admits, to a disgusted Zero, that he knew everything. With the vampires attacking the school, Kaien admits it is no longer peaceful, but, as he swears to do no violence against vampires, it is not until the Hunters arrive that he, along with Yagari, go out to defend the Night Class. He goes up against the president of the hunter association, and discovers that the president has been partially taken over by drinking a powerful vampire's blood. He dispatches the president, but the Hunters take Kaien into custody for the disaster that has occurred.

During the following year, Kaien has been in custody while Yagari acted as the chairman of the academy. Yagari and he convince Zero to return to school, albeit allowing Zero the use of one of his apartments. Kaien is now acting as the President of the Hunter Association, and returned back to the school as the Chairman. It is revealed that Yagari is actually the true head of the Hunters Association.

Kaien goes to Zero, who reveals to Zero that the Hunter Association intend for Zero to become their president in the future, and require him to attend the peace meeting. Kaien also tells Zero that he will stand between Yuki and Zero, if necessary, because he cares for both of them. Kaien attends the meeting with various other hunters. The meeting goes smoothly although Kaname interrupts the meeting to inform Kaien that he will be able to see Yuki at the party, to which Kaien thanks him. Kaien expresses doubts over the way Kaname dealt with the former Vampire Council, believing it to be too harsh, and at risk of alienating the other vampires, in particular the other purebloods.

Kaien goes to see Yuki at the party, but expresses displeasure toward Kain over the difficulty in seeing her. His visit is delayed when they discover the body of a hunter. He gets to see Yuki when she walks into the room, but he finds it difficult to tell that a hunter was bitten by a pureblood. After Ouri's death is considered an assisted suicide, Kaien declares that the Hunters can never let it happen again.

He is later seen in Shouta's house, and questioned why he didn't greet Yuki before she left. He responds by saying it's fine considering that he just saw her the other day, and didn't want her knowing that they were old friends, since it might influence her way of seeing things. He then goes off ranting about how adorable she is, and how painful it's going to be if someone does chop off her head, even if she can't die from such an injury. He also states that she should take care of herself properly. Kaien then remarks about how much she does look like her mother, and how the purebloods shouldn't look at her that way. He then goes on saying that he felt as if he made a difference, and it convinced him to raise a vampire child for ten years. He decided to hold onto the theory of 'what if,' and go for it. He did it to try and make ripples on the surface, and that Yuki grew up watching that. He then says that he doesn't want to delay him anymore, and that he still had more visits to make. He just suspected Shouto would wake up soon. and he just wanted to say hi. Kaien them warns him that the hunters are still in uproar about the incident with Ouri, so he shouldn't cause any trouble.

Juri Kuran
Kaien and Juri met as enemies when Kaien tried to kill her and they eventually became good friends.

Powers
Kaien is a very strong hunter, known as the best until he retired. Kaien is unusual amongst the vampire hunters, having stopped aging at 25 years old, they have been studying his DNA, which he is said to possess extremely high amounts of vampire DNA that stopped his aging and causes Zero to confuse him with that of a vampire's aura. Like all vampire hunters, Kaien is able to wield anti-vampire weapons and carries a sword hidden in a cane and he has an acute smell that senses vampires.

Trivia

 * Cross or Kurosu, means "black master." Kaien is a combination of kai, meaning "ashes", and en, meaning "village gate." The kanji for en is also used for Enma the ruler of the Underworld in Buddhist mythology.
 * Kaien often asks Yuki to refer to him as "father" when she calls him "Headmaster".
 * In the manga, when Zero was tamed, Kaien says something along the lines of "If you ever need to drink someone's blood, feel free to drink mine!". In the same panel, his chest reads "GAY".