Zero's younger twin brother. When Zero and Ichiru were young, both were trained and cared for by Touga Yagari. Unlike Zero, Ichiru did not exhibit the same natural abilities due to his frail health and frequent illnesses. Despite this, Zero and Ichiru shared a close bond during their childhood. However, Ichiru claimed to hate Zero after overhearing that their parents favored Zero as a hunter.
Ichiru had connections with Shizuka regarding the murder of his parents. He admired and deeply cared for Shizuka, who he believed 'rescued him from loneliness.' Serving as Shizuka's bodyguard, Ichiru received her blood in return, which cured his weak constitution. Although he wished to become a vampire, Shizuka refused to turn him into one.
After Shizuka's death, Ichiru drank her blood before Zero could. Disappearing after this incident, he later returned to Cross Academy as a student but revealed he worked for the senate. After attacking Rido Kuran in revenge for Shizuka, Ichiru was severely wounded. Realizing he was near death from blood loss, Ichiru decided to shoot Zero to trigger his thirst for blood. His intention was for Zero to consume the remainder of his life, thus acquiring the full potential of power he should have had since birth. Ichiru's final wish was for Zero to live on and accomplish what he himself could not.
