Jimmy Kudo, a 17-year-old high school prodigy and detective who frequently worked with the police, was attacked by two members of a mysterious crime syndicate while investigating a case regarding blackmail. He was then forced to take a newly developed experimental poison that was supposed to kill him, but due to a rare side-effect unknown to the two men, the drug transformed his body back into that of his seven-year-old self instead, after they left him for dead. In order to hide his identity and investigate the whereabouts of the syndicate, which he later finds out is called the Black Organization, he adopts the pseudonym Conan Edogawa.