Chief heads Shinjuku's police force. He commissions shelters to protect citizens during Eko's attack, maintaining a human facade. This disguise conceals his true nature as Ushi-oni, a yōkai living among humans. His history includes a prior attack on Sagisaka Minoru's daughter, Yoshiko, at her school. Witnessing this event led to Yoshiko's institutionalization after authorities dismissed her account of a supernatural assailant, directly linking him to the Sagisaka family's trauma.

During the climax, Chief herds human refugees, including Otoha, Kure, Hinaru, and the Sagisakas, into one of his shelters. There, he reveals his monstrous Ushi-oni form—a mechanized, bull-like entity. He immediately attacks the survivors, consuming humans alive. Flashbacks enable Yoshiko to recognize him as her past attacker. Sagisaka sacrifices himself to save Yoshiko from Ushi-oni's assault, but the yōkai continues his rampage. Otoha confronts him to defend the remaining humans, sustaining severe injuries. Following Otoha's resurgence as Karas, empowered by Yurine's revival, Ushi-oni is slain in the ensuing battle.