In order to die, he chose to become a detective… The year is 2030. The Boy Detectives Club is brought together by mysterious private detective Kogoro Akechi. These boys have been instructed in how to solve a wide variety of cases, big and small, using their inherent ability to take action. One day one of the members, Kensuke Hanasaki, meets an enigma of a boy, Yoshio Kobayashi. Kobayashi, who possesses a body that cannot die due to an unidentifiable mist, wishes only for his own death and rejects contact with others. Intrigued by the other boy’s existence, Hanasaki suggests that Kobayashi joins the Boy Detectives Club. The meeting of these two boys finally becomes entangled with the criminal of the century, the Fiend with Twenty Faces, and Kogoro Akechi, affecting their fate.