Kuro is the central figure of the anime Kurozuka. In his original lifetime, he is a swordsman living in 12th‑century Japan. After a defeat at the hands of his elder brother, he flees into the mountains with his servant Benkei. There he takes shelter in the secluded home of a mysterious woman named Kuromitsu. During his recovery from illness, he discovers that she is an immortal vampire. The two fall deeply in love, and when Kuro is mortally wounded by pursuers, he drinks her blood to survive, beginning a transformation into an immortal being himself. Before the process can complete, Benkei, now subverted by a clandestine organization called the Red Army, betrays him and severs his head. This disruption leaves Kuro in a suspended state, and he reawakens centuries later in a dystopian, post‑apocalyptic version of Japan, his memories fragmented and much of his past missing.

At his core, Kuro is a stoic and introspective warrior. He appears taciturn and emotionally distant, yet underneath that surface he possesses a strong capacity for loyalty, compassion, and tenderness, especially toward Kuromitsu. His immortality has isolated him from ordinary human connections and burdened him with loneliness and quiet torment. He is fiercely determined, and his actions are driven by a single‑minded quest to find Kuromitsu and exact revenge on the Red Army for tearing them apart.

Throughout the series, Kuro serves as the driving force of the narrative. Initially a fugitive samurai, he becomes a supernatural wanderer trapped between eras. After his awakening, he allies himself with an underground resistance group called Haniwa, which opposes the Red Army’s tyranny. His primary motivation remains the search for his lost love, and he repeatedly confronts the Red Army’s enhanced warriors, who seek to exploit Kuromitsu’s blood. In the story, he is both a protagonist and a tragic figure, cycling through loss, memory, and obsession.

Kuro’s most important relationship is with Kuromitsu, the immortal vampire who is both his lover and the catalyst for his own immortality. Their bond is intense, carnal, and doomed, repeatedly interrupted by violence and betrayal. His connection to Benkei is equally defining: the lifelong servant who becomes a Judas figure, severing Kuro’s head and later emerging as the Red Emperor. During the post‑apocalyptic chapters, Kuro forges temporary alliances with members of the Haniwa, such as the sniper Rai and the leader Saniwa, though these relationships are often transactional or cut short by death. His interactions with Kuon, a complex agent who shifts allegiances, add further layers of manipulation and distrust.

Kuro’s personality undergoes subtle but significant shifts. In his feudal past, he is a calm and disciplined samurai, softened by his love for Kuromitsu and his willingness to abandon his former life for her. After his revival in the ruined future, he becomes more single‑minded and detached, driven largely by memory fragments and instinct. The series repeatedly strips away his clarity, culminating in a cyclical ending where he loses his memories once more and begins his search anew, underscoring a tragic lack of resolution and the eternal recurrence of his suffering.

Kuro is an exceptionally skilled swordsman, capable of defeating multiple opponents with precision and speed even before his transformation. Once he becomes a vampire, his physical abilities are greatly enhanced: he is stronger, faster, and can withstand injuries that would kill an ordinary human. In battle, he occasionally enters a heightened state — sometimes called a hyper‑mode — where his movements become a blur of lethal efficiency. His immortality grants him the ability to survive decapitation and reattach his head to a new body, though this process is imperfect and tied to his memory loss. Despite these powers, he remains vulnerable to psychological torment, fragmented recollection, and the manipulation of those who seek to control him.