Detective Minoru Sagisaka investigates serial murders in Shinjuku's Intervention Department alongside his partner Narumi Kure, focusing on cases where victims display drained blood—evidence he attributes to mikura entities. While colleagues dismiss supernatural theories, Sagisaka staunchly defends this explanation. His conviction originates from personal tragedy: his daughter Yoshiko witnessed a mikura massacre her classmates, only to be institutionalized when authorities rejected her account. Driven to validate Yoshiko’s testimony and free her, Sagisaka pursues survivors of similar attacks like Hinaru, whose encounters bolster his theories.

During Eko’s climactic events, Sagisaka, Kure, Yoshiko, and Hinaru barricade themselves in a shelter with civilians including Otoha. There, the shelter’s police chief morphs into Ushi-oni, a monstrous mikura, and attacks. Yoshiko identifies Ushi-oni as her childhood assailant. When the creature lunges at her, Sagisaka shoves Yoshiko clear, sacrificing himself to the fatal blow.