Umibōzu, whose name means "sea bonze" and refers to a ghost in Japanese mythology, is also known as Hayato Ijuin. He operates as a "sweeper" in the underground world much like Ryo Saeba. With his massive physique and exceptional combat skills, he doesn't require a partner. Umibōzu matches Saeba in many aspects, leading to a somewhat competitive relationship between them.
Back in Central America, Umibōzu faced off against Ryo and suffered eye injuries due to Saeba's actions. Despite this incident, which might have turned them into enemies, both men dismiss their past conflicts since what happened during the war wasn't personal. However, that doesn't prevent them from clashing. They frequently find themselves on opposite sides of the same case and have engaged in multiple duels.
Interestingly, Umibōzu harbors an irrational fear of cats.
