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 guardian of Zero Kiryu and adoptive father of Yuki Cross, the heroine of the story. In the first and second arcs, Kaien's role in the story is largely observant, and he takes little action until the hunter's association attacks the Night Class at the end of the second arc. After this point in the series, Kaien takes on a more direct role in the action.

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, often mocking him about being a vampire as he 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 used to intentionally pick fights with him. After befrending Juri and Haruka Kuran, Kaien took on Juri's dream of establishing a school for vampires and humans, and retired as a Vampire Hunter in order to establish Cross Academy 16 years prior to the story's beginning. Following the deaths of Juri and Haruka, Kaien took in their hidden daughter, Yuki, after Kaname Kuran brought her to him for safekeeping. Thus Kaien became Yuki's very doting and slightly odd father, much to Yuki's annoyance. Kaien also took in Zero Kiryu several years later, after the deaths of Zero's parents. As he did with Yuki, Kaien also wished to adopt Zero, but Zero refused.

Shortly after Zero's arrival, Kaien, with Kaname's assistance, is finally able to establish the Night Class to promote understanding between humans and vampires. Due to the vampire presence at the school, Zero initially refuses to attend high school and is left behind a year, but Kaien is later 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
At the beginning of the manga, Kaien is portrayed as the headmaster of Cross Academy and adopted father to Yuki and Zero. While he seems to be aware of what is going on at the school at all times, he leaves the enforcement of school discipline (particularly of maintaining the peace between the vampire and human students) to Yuki and Zero. The duo are Cross Academy's only school prefects, a fact which annoys Zero as he believes he needs more than Yuki's assistance in order to maintain order. After Zero completely awakens as a vampire, it is revealed that Kaien knew the truth behind the deaths of Zero's parents all along and that he had been the one to take Zero to get his tattoo in the hopes that it would slow down Zero's transformation into a vampire. Kaien also performs the ceremony to have Yuki tame Zero.

Later on, after Yuki's memories of the past begin to awaken, Kaien accompanies Yuki and Zero to the Hunter Association's main headquarters in order to look up the records on Yuki's history. While there, Yuki accidentally discovers Kaien was once a Vampire Hunter, a fact which does not surprise Yuki; however, Kaien states he is ashamed for having killed vampires in the past and didn't want her to know. Yuki responds that he is her father and nothing has changed. Kaien is touched.

Once Yuki's memories finally return and she reawakens as a Pureblood vampire, Kaien admits, to a disgusted Zero, that he knew everything about her past but kept silent. When the school is subsequently attacked by Rido's legion of vampires, Kaien attempts to maintain order, but it is not until the Hunters arrive that he, along with Yagari, go out to defend the Night Class, declaring that while the Night Class is protecting the human students, he will protect the Night Class. During this battle, Kaien fights and kills the acting president of the Hunter Association, discovering in the process that the president had been slowly transforming into a vampire after drinking the blood of powerful vampires. After the battle ends, the Hunters take Kaien into custody in an effort to hold him accountable for failing to keep the school safe.

As both the strongest living Vampire Hunter and the person responsible for the death of the former president, Kaien is ordered to take responsibility for his actions by becoming the new acting president of the Vampire Hunters, a role he is to assume until Zero comes of age to take the job himself. Kaien does not particularly care for the job; however, he recognizes that Zero is not yet ready for the position, so along with Yagari, who plays the part of Kaien's unofficial "co-president," the two manage to return order to the Vampire Hunters after the betrayal of their leader.

After the events at Cross Academy, Kaien's relationship with his two adopted children changes dramatically. Having left with Kaname after the battle, Kaien and Yuki are separated for an entire year and have no contact with one another due to Kaname's orders that Yuki must stay hidden in Kuran manor. Because of his confinement by the Vampire Hunters, Kaien is also unable to see Zero for a number of months after the battle. When the two finally reunite, Kaien discovers that Zero has gotten his own apartment and has been attending school during the day, while hunting vampires at night. Concerned for the wellbeing of both of his children, Kaien tells Zero that he will stand between them should it ever become necessary.

During this time, Kaien attends a meeting between the Vampire Hunters and Kaname, who has now installed himself as the leader of vampire society. 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. He also questions whether or not Kaname will be able to keep the rest of vampire society in line, to which Kaname responds that the answer to his question will be in how many vampires choose to attend the ball being given in honor of the continued cooperation between the Hunters and vampire society.

It is at the ball that Kaien and Yuki are finally reunited, though the two are unable to speak with one another, much to Kaien's displeasure. After the mysterious death of Ouri, a Pureblood attending the ball, at the hands of a Vampire Hunter who was turned into a vampire and then forced to kill him, Kaien, along with Zero, takes the lead in the investigation. Nominally determined to have been a suicide, Kaien declares that the Hunters must never again let anyone else be killed so that a Pureblood may end his own life.

Kaien is later seen in Isaya's house, just after Yuki's visit with him. When Isaya asks why Kaien didn't greet her before she left, he responds that it's fine since he didn't want her knowing that they were old friends, in case it influenced her way of seeing things. Kaien also remarks on how much Yuki has come to resemble her mother, but clarifies that he does not hold romantic feelings for Yuki at all. When Isaya comments that seeing Kaien as a father is something he never could have imagined, that he'd always thought Kaien would remain a neutral spectator just as he himself is, Kaien responds that by opening the school and caring for Yuki, he realized he could make a difference. He thinks that it is important that Yuki grew up watching that.

Shortly after Kaname attacks the Pureblood Touma, Zero brings Hanabusa Aido into Vampire Hunter Headquarters for questioning about Kaname's plans. Unable to get any information out of Aidou, Kaien decides to return him to Kuran manor. On the way home, thw two are unexpectedly flagged down by Yuki who insists they drive to the Hanadagi family manor. Upon arriving at the scene, Yuki, Aidou, and Kaien witness Kaname beheading Aidou's father after having killed the Pureblood Hanadagi. Kaien attempts to pursue Kaname after the death of Nagamichi Aidou; however, Kaname escapes. Kaien then encounters a distraught Yuki who insists on following after Kaname. Kaien tells her that as her adpotive parent, he is unable to allow her to follow after Kaname due to his inexplicable actions.

After returning to Vampire Hunter Headquarters with Yuki and Aidou, Kaien questions Yuki about Kaname's plans. Unable to provide any information, Kaien allows Yuki to take the lead in attempting to track down Kaname for questioning in the murder of Nagamichi Aidou.

Juri Kuran
Kaien and Juri met as enemies when Kaien tried to kill her and they eventually became good friends. There is some suggestion that Kaien may have held romantic feelings for her. What is clear, however, is that Kaien held both Juri and Hruka Kuran in high regard during the years of their friendship.

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".