Ichiru Kiryu

Ichiru Kiryu (錐生 壱縷, Kiryū Ichiru) was the younger twin brother of Zero Kiryu. When they were children, they were both taught by Toga Yagari to become vampire hunters. Ichiru, however, did not seem to have the same talent as Zero's natural ability, as he was often ill.

Appearance
Ichiru and Zero both bear a striking resemblance as they both have silver hair and lilac eyes with a tall and slim build. The differences between Zero and Ichiru is that Ichiru has slightly longer hair than Zero and Zero has a tattoo and piercings. In the anime's second season, Ichiru styled his hair into a short ponytail with Shizuka Hio's pink string that had a bell attached to it. Upon meeting his twin brother for the first time in four years, Ichiru wears a plain white mask covering his eyes, though discards the disguise when Zero recognizes him. Like Zero, Ichiru is considered attractive by the Day Class girls.

Personality
Ichiru was a complicated person who was marked by many conflicting emotions and actions. Although he was very close to Zero as a child, Ichiru nevertheless struggled with the inevitability of being left behind by his brother as well as the strain of not being able to make it as a hunter. He eventually became jealous because of how Zero could be healthy and normal while he couldn't. Though professing to both love and hate Zero upon different occasions, Ichiru didn't always appear to know his own mind when it came to his twin, but his actions indicated that in whatever way, Zero was incredibly important to him. The only other person who was just as important to him in his life was Shizuka Hio, but he was heartbroken and angry when she died.

History
Ichiru was born into the Kiryu family, a distinguished family of vampire hunters, as Zero Kiryu's twin brother and due to the hunters' curse, most if not all of his hunter powers were absorbed by Zero, which subsequently gave the latter increased power as a hunter. Even though his parents were highly skilled vampire hunters, they were both killed by Shizuka Hio when she attacked the Kiryu household one winter night after Ichiru left the house.

Plot
After the death of his parents, Ichiru and Zero Kiryu have no communication with one another for four whole years, due to Zero believing his brother to be dead just like his parents. Despite Shizuka Hio allowing Ichiru to drink her blood in order to strengthen him and cure his chronic ill health, she didn't turn him into a vampire and instead chose to keep him as a human.

Through the raven's eyes, a mysterious girl claims that she will start attending Cross Academy, while stating that Zero looks very cute now, and that Yuki looks very delicious. Next to her, Ichiru listened with jealousy.

Ichiru arrives at Cross Academy in a carriage with Maria.

Meanwhile, Maria is with her bodyguard. Maria looks out the window talking to herself, saying that Zero is so cute by looking at her with those hostile-like eyes. Maria goes back to her bodyguard and says, in front of his face, saying that jealousy doesn’t suit him. Then she moves in closer as if to bite him on the neck, but decides not to, who he becomes angry, and comes back to facing the window and says “This is so much fun.”

Zero remembers telling Ichiru, his twin, to flee after Shizuka’s attack. Presently, he and Yuki are on duty for the Night Class, but the evening is quiet due to upcoming exams.

Ichiru watch Kaname and Maria converse in Kaname's office before he leaves with Maria.

Zero faces down Maria but can’t kill her. She says he can’t kill his master, who made him a vampire. She tries to kiss him, but he jerks back. When Ichiru throws down a sword to Maria, she and Zero fight. Alarmed, Yuki calls his name, but Kaname puts her asleep. He erases Yuki's memory of that night, saying that he cannot lose Yuki but that Zero can die if he’s that weak. Zero faints from an injury, and Maria tells Ichiru to carry him away.

Meanwhile, Zero dreams of Shizuka and Ichiru. Zero recalls as a child that he and Ichiru discreetly meeting Shizuka. Upon first seeing her, Ichiru finds her beautiful but Zero sensed that she’s a vampire during the day. Ichiru says that Zero's amazing and makes up for Ichiru's mediocrity. That night, Ichiru asks if the vampire they saw earlier will be killed and if kindly Zero will be able to hunt vampires. Zero says Master will teach him to. When Shizuka suddenly appeared at night and attacked Kiryus, out of revenge for killing her lover. Zero sees Ichiru standing next to Shizuka, smiling. Zero wakes up and sees Maria's bodyguard, he coldly greets him and told him to take off the mask, who he knows is his twin brother. The bodyguard removes his mask to reveal himself to be Ichiru.

Zero faces Ichiru, who reveals his past feelings of envy and worthlessness and how he and Shizuka became allies. Ichiru tells Zero that even though he wants to kill Zero, he won’t if Zero serves Shizuka. Zero apologizes for getting Ichiru turned into a vampire. Angry, Ichiru attacks. Zero blocks it but keels over, overcome by blood thirst. Toga bursts through the door to retrieve Zero. Ichiru challenges him, but Toga refuses to fight, saying that Ichiru was his disciple. Angry, Ichiru draws his sword. Zero steps in to defend his teacher. Ichiru is knocked over by Zero’s strength and his sword flies through the air. It falls straight for his throat, but Toga takes the blade in his shoulder, shielding Ichiru, who leaves with his sword when Zero takes it out.

Zero shoots his own leg and the pain breaks his compulsion. He wounds Shizuka with the Bloody Rose. Zero again points the Bloody Rose to Shizuka again but Ichiru enters, throwing his sword into Zero's firing arm. While Zero is pulling out the sword, Shizuka tells Ichiru not to meddle and leaves. Zero tries to go after Shizuka but Ichiru blocks him and tells him is he playing on leaving again. Zero angrily says to Ichiru that he was the one who left, who meant the vampire world.

Yuki asks Zero who Ichiru is. Ichiru says to Zero isn't he going to introduce them. Zero tore the mask off of Ichiru and says to Yuki that he's his twin brother. Yuki became surprised that Ichiru has the same face as Zero.

Ichiru pulls out a dagger and begins fighting with Zero. Then, Yuki jumps between them and say they shouldn't as they are brothers, and Ichiru threatens to kill Yuki against Shizuka's orders. Zero retaliates by pressing his gun to Ichiru's head, but Ichiru reveals that it won’t work on him because he’s still human. Zero lowers his gun and says he knew it. Ichiru becomes enraged, explaining that although Shizuka gives him her blood, she doesn't want his in return. He loves her, but like their parents, Shizuka seems to prefer Zero over him. Ichiru pushes Yuki out of the way to attack Zero.

All the vampires smell blood. Zero tells Ichiru that the smell of blood is strong and Ichiru realizes that it’s Shizuka's. He leaves to find her. Ichiru has already reached Shizuka and finds her dying on the floor.

As Shizuka dies, Ichiru cries and they share flashbacks of their past. Ichiru has been in love with her since they first met. Shizuka ignored his feelings and refused to turn him into a vampire but freely gave him her blood. Even now, Ichiru offers his blood to save her, but she rejects him. Fond of Ichiru, Shizuka cannot curse him like that. Seeing Ichiru cry though, she tells him that they will always be together and pulls him towards her. Zero finds them as Ichiru is licking the remains of something from his lips. Shizuka’s corpse dissolves into the air.

Zero rushes into the room and finds Shizuka and Ichiru as Ichiru is licking the remains of something from his lips. Shizuka’s corpse dissolves into the air. Meanwhile, the puddles of her blood everywhere have stimulated Zero’s level E impulses and he collapses. Ichiru relates the hatred Zero feels for him. Zero tells him that Shizuka wanted you to stay the way you are not a vampire. Ichiru taunts him. Zero calls out to Ichiru but he disappears.

Meanwhile, Zero has been assigned to oversee the party by the Hunter's Association. Zero senses Shizuka, looking around and finding Ichiru at the ball and begins to look for him. Zero noticed his younger brother and followed him as they talk briefly, who revealed that he became employed by the Senate after Shizuka’s death and working for the Vampire Company. Ichiru asks Zero if he has heard of the "Curse of the Hunter Twins." Zero became confused before Ichiru left.

The episode started off with Senri visiting his uncle; Ichiru was found in the same residence.

Ichiru reappears as a Day Class student attending Cross Academy under Rido Kuran, Senri Shiki's father's orders (and by Zero's permission).

Ichiru is charismatic and quickly becomes popular among the students, a stark contrast to his older brother. When Zero enters the classroom, he and Ichiru talk alone for awhile outside before Ichiru walks away. After a talk with Zero about his courage to face his brother, Yuki resolves to talk to Kaname once more about her past.

When Yuki collapses from these images, she is taken to the infirmary, where Ichiru attempts to give her a vial of blood, and he suddenly has visions of Shizuka and Zero then is stopped by Hanabusa, who takes the vial.

Yuki and Headmaster Cross try to invite Ichiru to dinner in an attempt to have Zero and Ichiru reconcile their differences. However, Yuki brings up that she saw Ichiru in the infirmary and thought he was Zero. Zero's furious response to this causes Ichiru to leave. He tells Kaien that it's too late to choose a different path. Later Ichiru tells Zero not to fall in love with Yuki.

Zero notices Ichiru with 'Senri'.

Meanwhile, Kaname goes to where Rido is being kept and finds Ichiru there. As Ichiru opens the coffin, Kaname tells him that usually, hunter twins will kill their sibling while still in the womb, and that Ichiru is the first he has met to have been born with his twin and Zero was kind-hearted before he was even born. Ichiru arrives in the prison cell and shoots Zero with the Bloody Rose he picked up, wounding him. Zero recalls the close and loving relationship he had with Ichiru when they were children and remembers Shizuka killing his parents. Ichiru, revealing that he was injured while attempting to kill Rido for Shizuka's sake because it was Rido, who was the one who put her lover on the list. Ichiru asks Zero to consume his blood so that they can "become one". Ichiru is happy when Zero says he doesn't wish for Ichiru to die as he still had some love for his little brother and that Maria wishes to see him. Pretending to die from his wound, Ichiru succeeds in making Zero consume his blood so Zero can complete his vampire hunter powers to control his thirst for blood. Zero leaves the bell Ichiru kept as a memento of Shizuka in his brother's hand before leaving the prison cell.

Zero stops convulsing and feels that the pain he is feeling is proof he and Ichiru have become one. Grabbing his Bloody Rose, Zero points it at Rido as the weapon begins glowing. After Ichiru's death, Zero appears to have grown vines, which most likely were from all of Shizuka's blood that Ichiru had ingested to prevent his chronic illness from returning. During the one year time-skip, Zero is seen visiting Ichiru's grave and he laments on how he fears he's forgetting how to feel like a human. Ichiru then appears as a spirit to comfort his depressed. He calls Zero silly and to remember that his body may be within a grave with his parents, but his soul has become a part of Zero's so he remembers for him what it's like to be human. Lastly, he retells Zero to follow his heart before disappearing. When Yuki is drinking Zero's blood, she sees Ichiru within his memories along with the human version of herself standing beside a coffin covered by vines.

Powers & Abilities
Though he was born into an elite vampire hunter family, Ichiru was a very sickly child who was not strong enough to become a vampire hunter along with possessing no talents for it due to the curse. However, after being taught how to become a hunter by Toga Yagari and drinking Shizuka Hio's blood, he's shown as being much stronger then he had been as a child. He was skilled with a sword.

Equipment

 * During Zero Kiryu's fight with Shizuka Hio while she was in Maria Kurenai, Ichiru throws Maria a dagger that helped wound Zero fatally.
 * While Zero Kiryu was held captive when he tried to kill Rido Kuran, Ichiru had a sword on him.
 * In the last minutes of his life, he shot Zero in the shoulder with the Bloody Rose.

The Kiryus
His parents worried about Ichiru's health and his chances of him becoming a hunter. After hearing a conversation about this, Ichiru took this as them favoring Zero over him and felt as of they were being watchdogs for the Vampire Hunters Association. Ichiru assisted Shizuka with the murder of his parents.

Zero Kiryu
Zero is Ichiru's older identical twin brother whom he shared a close relationship in their youth, as Ichiru grew older, his jealously of Zero caused him to hate Zero for the simple fact that Zero became a vampire and he didn't along with Zero's superior skills as a hunter. The younger Ichiru was more cheerful, unlike Zero who doesn't talk much. Ichiru claims he wanted Shizuka to keep him alive only because he wanted Zero to suffer.

Before the war with Rido Kuran, he seeks Zero once more and asks him to consume him, so that he can once more become a part of his brother. Ichiru is happy when Zero says he doesn't wish for Ichiru to die; meaning Zero still had some love for his little brother. Zero ate Ichiru (another meaning for taking in Ichiru Kiryu's blood so they would be one like how they were supposed to before they were born). Ichiru's dying wish is for Zero to live on and complete his goal. Even after death, Ichiru's spirit often comforts Zero as the hunter questions whether he is losing his humanity.

Shizuka Hio
Shizuka is the person Ichiru betrayed his parents and Zero for. She told Ichiru that if he lets her take revenge on his parents for her lover she will make his body become stronger. He agreed but it is later found out that he asked her to keep Zero alive. Ichiru served her as her butler and at some point it is pointed out that he loved her, despite the fact that she killed his parents and turned his brother into a vampire. Upon her death, she gives him a bell on a ribbon to which Ichiru proceeds to tie his hair up. Shizuka allowed Ichiru to drink her blood but refused to turn him into a vampire, much to Ichiru's dismay.

Maria Kurenai
It is hinted that Maria may have romantic feelings for him. Maria has a strong attachment to Ichiru and is quite fond of him, to the point where she persists in searching for him long after she has left the academy.

She appears to have spent a great deal of time with him while he was living with Shizuka and admired Ichiru's kindness towards her. He express concerns over her well being and chides her silly behavior standing out in the sun; Zero mentions to Ichiru before his death that Maria wishes to see him.

Yuki Kuran
The two often met at the end of differing sides. Ichiru threatened Yuki continuously knowing that she is one of Zero's weaknesses something Yuki didn't realize at that point in time. Yuki tries to be civil when confronting him but unlike Zero finds herself uncomfortable in Ichiru's presence. He often spoke to Yuki in a condescending manner and even questions out loud why Zero would spend time in her presence. Ichiru knew there was more to Yuki's background and often warned Zero to stay away from "that girl" and telling Zero that his taste had run bad.

After Ichiru dies, Yuki feels sadness after seeing Zero carry his deceased brother's body to be buried.

Kaito Takamiya
In the Vampire Knight light novel "Season of Transience", Kaito seems to dislike Ichiru because he is ill and sickly, and gets in their way.

Trivia

 * Ichiru (壱縷) is a combination of Ichi ( 壱 ) meaning one and Ru (縷) meaning rage. His surname, Kiryu, consists of the characters for auger (錐, kiri) and life (生, nama).
 * Ichiru's Good At: Humanities (though he hates studying.)
 * Ichiru's Hobbies: Things concerning Zero.
 * Ichiru's Respects: Shizuka-sama.
 * Ichiru's Favorite Fashion: Anything Zero or Shizuka-sama chooses for him.
 * Ichiru's Taste in Women: "A beautiful, older woman."
 * Ichiru's Treasure: The bell Shizuka-sama gave him that he sometimes wears in his hair. (anime only)
 * Ichiru's Favorite Food: Anything made by Zero.