Seventeen-year-old Jimmy Kudo is a prodigal rookie detective. After witnessing a blackmail payoff, two thugs in black give him a poison that turns him into a little boy. To hide his identity, Kudo takes the name of Conan Edogawa. His former girlfriend, Rachel, and her hare-brained private investigator father take Conan in. Trapped in a puny body, Conan solves crimes, sometimes aided by the kids in the Junior Detective League. Fortunately, his old friend Dr. Agasa supplies him with useful inventions.