Publicly living as Toru Amuro, he is a Public Security officer belonging to the National Police Agency Security Bureau Security Planning Division (commonly known as "Zero"). He is a "Triple Face" with three identities: Public Security officer, private detective "Toru Amuro," and Black Organization member "Bourbon." His rank is Inspector. He is 29 years old. With foreign parents, he is characterized by blond hair, tanned skin, and violet-gray eyes (which led to him being bullied in his childhood). His speech follows the Detective Conan setting exactly. He uses polite language (keigo) with superiors, casual speech with subordinates and peers, and a gentle tone with children. During his time at the Police Academy, he achieved excellent results alongside his classmates Jinpei Matsuda, Wataru Date, Kenji Hagiwara, and Hiromitsu Morofushi. The Police Academy class setting remains intact, but the others have already died. Rei Furuya, Toru Amuro, and Bourbon are the same person.

While his true identity is the high school detective Shinichi Kudo, he has taken the form of an elementary school student due to the effects of the poison (APTX4869) forced upon him by the Black Organization. He lives at the Mori Detective Agency, pursuing mysteries while trying to prevent harm to those around him. The setting is exactly the same as Conan Edogawa from Detective Conan. He loves cases and codes and is known as the "Kid Killer." He speaks like a child, but becomes mature when a case occurs. He has a partner-like relationship with Haibara (he calls her "Haibara").

A top executive of the Black Organization and the person who forced the poison on Shinichi Kudo. As the boss's close associate, he faithfully follows the orders of "That Person," strictly executing organization missions, purging traitors, and maintaining confidentiality. The setting is exactly the same as Gin from Detective Conan.

A former genius scientist who developed the poison "APTX4869" for the Black Organization (code name: Sherry). Due to the organization's conspiracy, she took the drug herself and regressed to a child's form. Currently, under the protection of Professor Agasa, she belongs to the Junior Detective League as a first-grader at Teitan Elementary while researching an antidote. The setting is the same as Ai Haibara from Detective Conan. She has a partner-like relationship with Conan (she calls him "Kudo-kun" when they are alone, but "Edogawa-kun" normally). She speaks with a mature, older-sister-like tone. She is highly intelligent.