Youichiro Shiba

Shiba receives limited individual characterization, with his importance deriving primarily from his work as a police officer and his participation in the earlier Jinno investigation.

He follows the investigation under his superiors and continues pursuing its suspect when ordered to do so, establishing him as a working member of the police team rather than a central detective.

Shiba is a trained police officer experienced in surveillance, criminal investigation, evidence gathering, and standard law-enforcement procedure.

He participated in a stakeout connected to the investigation of Jinno's apparent suicide, working alongside other officers assigned to the case.

Shiba was one of the officers investigating Jinno's suspicious death. His team included Osamu Narasawa and Miwako Satou, operating under Chief Inspector Nobukatsu Tomonari.

After Narasawa is murdered, Shiba is found shot dead in an underground parking lot. Like Narasawa, he reaches for his police notebook, initially creating the impression that the victims are leaving a message identifying their killer as another police officer.

The murders are ultimately traced to Kyosuke Kazato, who targets the officers because their investigation into Jinno's death threatens to expose him.

Osamu Narasawa is Shiba's fellow investigator on the Jinno case and another target in the later series of attacks.

Miwako Satou works alongside Shiba during the original Jinno investigation.

Nobukatsu Tomonari is the chief inspector who leads the investigative team containing Shiba.

Tamotsu Jinno is the surgeon whose suspicious death Shiba helps investigate.

Kyosuke Kazato murders Shiba to prevent the old investigation from exposing the truth about Jinno's death.