It is the 2030s. The Boy Detectives Club gathers under Kogorou Akechi, the mysterious detective. The group solves cases great and small using their unique skills. One day, a member of the club, Kensuke Hanazaki, meets the boy Yoshio Kobayashi. Kobayashi's body cannot die due to the effects of the "Unidentifiable Mist," but he yearns for death, and...