OVA
Description
Domon is a police officer in Tokyo who serves as the superior, mentor, and close friend of Senji Kiyomasa, also known as the Crow or the Red Knife Wielder. His background is tied to the aftermath of the Great Tokyo Earthquake, during which he was assigned with a team including Senji, Akira Shindō, Tōshirō Kan, and Momoi to help control the rampant violence in the city. In this period, he and his colleagues relied heavily on Senji's power, as Senji already possessed his Branch of Sin and used it to subdue thugs.

In terms of personality, Domon is depicted as clear-headed and perceptive, possessing a deep understanding of the world and human nature, insights he often shares with Senji. He holds a strong sense of justice, believing that police officers who beat up criminals for their own satisfaction are no better than the lawbreakers themselves, and Senji regards him as a very righteous man. Domon is also an avid smoker and is frequently seen with a cigarette. He is deeply protective of his fellow officers, especially Senji, and acts as a fatherly figure who tries to guide and raise them.

Domon's primary motivation stems from his protective instincts and his belief in proper justice. A key event demonstrating this occurs when Senji receives a challenge for a final battle from the criminal Ikazuchi Akatsuki. Instead of allowing Senji to go, Domon punches him in the stomach, gathers his team, and goes to face the challenge himself to protect his protégé. This act of sacrifice defines his role in Senji's backstory, as Domon and the others are brutally slaughtered by Akatsuki and his men before Senji can reach them.

His relationship with Senji is the most critical aspect of his character. Domon is not only Senji's superior but his mentor and friend, guiding him with wisdom about life and responsibility. In his final moments, as he lies dying and reaching out with a severed arm, he asks Senji for a cigarette. His last words to the distraught Senji carry significant weight: he admits that Senji was a burden to him and calls him a brat, but explains that depending on others is a specialty of children, while acting cool is a specialty of adults. He reassures Senji that the day will come when he too will feel good about being relied upon.

Domon's development occurs primarily through his death and its aftermath, serving as a crucial turning point for Senji's character. The tragedy of his loss and his final lesson about dependence and maturity continue to influence Senji's actions and worldview throughout the story. Domon is deceased, killed by Ikazuchi Akatsuki in the manga.

Regarding notable abilities, Domon does not possess any supernatural powers or Branches of Sin. He is a standard police officer whose equipment includes a gun, handcuffs, and other standard tools on his police belt. His strengths lie in his mental clarity, wisdom, leadership, and his unwavering sense of justice rather than any special combat abilities. He is consistently seen in his police uniform, with short, messy hair that is grey on top and black on the sides, and he has a goatee.
Cast