Sayoko Iwai

Iwai is authoritative and highly deferential to the institutional priorities of Public Security. She expects subordinates to follow decisions made within the department even when questions remain about the evidence or the direction of an investigation.

Her approach frustrates Makoto Kusakabe, who has previously challenged prosecutorial decisions involving informants. Iwai is more concerned with maintaining the established chain of authority than accommodating his personal objections.

She nevertheless works directly with Kusakabe and trusts him as a senior subordinate, making his involvement in Kogoro's case especially significant.

Iwai is an experienced prosecutor with authority within the Tokyo District Public Prosecutors Office. Her position gives her supervisory responsibility over major cases involving Public Security.

She understands the unusual relationship between prosecutors and Japan's security apparatus and is accustomed to handling cases involving confidential investigations and sensitive evidence.

Iwai has no established combat abilities. Her power is institutional, derived from her senior prosecutorial position and her ability to make decisions concerning investigations and prosecutions.

Iwai supervises the prosecution after Kogoro Mouri is arrested in connection with the Edge of Ocean explosion. Makoto Kusakabe serves beneath her while evidence apparently linking Kogoro to the attack is examined.

Her relationship with Kusakabe also extends to the earlier case involving Fumikazu Haba. When Kusakabe previously asked for leniency after revealing that Haba had acted under his direction as an informant, Iwai refused to abandon the prosecution, while assuring Kusakabe that his own career would not be damaged.

During the wave of IoT attacks, Iwai herself becomes a victim when an Internet-connected device is manipulated to electrocute her and ignite her hair. The incident forms part of the escalating cyberterrorism used to spread panic across Tokyo.

Conan eventually discovers that Kusakabe is responsible for the cyberattacks. Iwai's earlier decisions concerning Haba form part of the institutional conflict that contributed to his resentment toward Public Security.

Makoto Kusakabe is Iwai's subordinate in the Public Security Department. [Sayoko Iwai previously rejected Makoto Kusakabe's request to drop the case against his informant Fumikazu Haba, and Kusakabe later includes Iwai among the people endangered by his cyberattacks.](#spoiler)

Fumikazu Haba's arrest brought Iwai into conflict with Makoto Kusakabe. She was responsible for the prosecutorial response when Kusakabe admitted using Haba as an informant.

Kogoro Mouri's arrest becomes one of the major cases handled under Iwai's authority.

Rei Furuya represents the Public Security Police whose institutional influence shapes the investigation and prosecution surrounding Kogoro Mouri.