Yuichiro Hyakuya

Human: Yuichiro has medium-length, slightly tousled black hair. He has sharp green eyes. Yuichiro wears the standard YAIID uniform. It consists of a black long-sleeved coat with light green details, including epaulets on the shoulders, a brown shoulder strap running diagonally across his right shoulder, and two rows of gold buttons in the front. Along with this, he wears a pair of white gloves and a white belt with a gold plate. He also wears uniform trousers and black boots worn over leggings. Yuichiro carries a katana on his left hip. He is sometimes seen wearing a hat, and also often a cape.

When Ashuramarū, his demon from the katana, possesses Yui, his appearance and behavior change. Yui's eyes turn crimson, two black horns grow from his head, his teeth become pointed, and maroon markings appear on his face. In extreme cases, his hand may briefly appear inhuman. In his demonic form, Yui alternates between sincere deception and furious threats to achieve his goals. Attempts to persuade Mika to release him include tempting her with his own blood and promising to run away together if only Mika releases him. If not freed from his bonds, Yui wants to kill and destroy everyone around him. He screams and rages, claiming he will devour their souls. When Yui regains his human mind, he has no memory of his actions in his demonic state. Despite this, he seems utterly unconcerned by the loss of his humanity. Before he was given the drugs to suppress his demonic side, the squad noticed that Yui had become more cold-blooded towards everything. According to Ashuramaru, he is capable of thinking much more rationally without all those emotions. Although Yui could consider an alliance with vampires they couldn't defeat and from whom they needed information, Yui is instantly consumed by murderous rage at the sight of something deeply disturbing. After taking the drugs, Yui's personality returns to what it was before he became a Namari.

In his incomplete seraphim form, Yui's left eye darkens and bleeds, and a massive wing-like structure grows from the top of his left shoulder. As a full seraphim, Yui has one pair of irregularly shaped black wings (a result of Ashuramaru attempting to prevent the transformation), both his sclera are dark with golden irises, and the tips of his hair turn white. During his first transformation, Yui becomes enraged and attempts to kill anyone nearby. He shows no interest in vampires and recognizes no one, but tells the vampire not to interfere. He also mumbles that "sinners must die," and he must kill all sinners, approaching Shinoa with a sword. Yui's partial seraphim form reacts with anger to her embrace.

During his second transformation, under the influence of the seraphim known as the King of Salt, Yui curses the corrupt people and plans to turn them into "pillars of salt." He defends himself against Abaddon, a monster summoned by another seraphim. He then proceeds to strike the monster before turning his attention to the people.

Revenge on the vampires. Yuichiro strives to destroy all vampires on Earth because of what they did to his family. Courage and fearlessness. Yuichiro is willing to risk his life to protect others. Perseverance. He doesn't give up, even when he is plagued by setbacks and defeats. Loyalty. Yuichiro is devoted to his family and friends, always ready to help when they are in trouble. Selflessness. He puts the interests of others above his own. Directness. Yuichiro openly states his goals and intentions, without paying attention to the approval or opinions of other people. Emotions and feelings Guilt. Yuichiro blames himself for the death of his family and Miki's "perishment," and he has nightmares about the event. Compassion. He empathizes with those who have had loved ones taken by vampires, such as the civilian girl who gave his unit false information because her parents were being held hostage. Love for Mika. Mika becomes the meaning of Yuichiro's life; he is ready to sacrifice himself for his friend. Relationships with other characters With Mika. Yuichiro loves Mika, wants to be with him in the future, and wants to raise children together. With Shinoa. At first, Yuichiro only has a superficial acquaintance with Shinoa, but later they develop mutual understanding and support. With Ferid Bathory. In his youth, Yuichiro hated Ferid, who used Mika and killed his family, but later agrees to a truce to save Ferid and her friends.