A kid who can't die meets a detective club, and the show spends its first eight episodes convincing you this is the most human thing you'll ever watch. The mystery-of-the-week structure collapses by the middle and never recovers, but those opening episodes establish something real: what it means to want death when your body refuses to give it to you. You're watching a show about loneliness disguised as a detective story, and it knows exactly what it's doing until it suddenly stops knowing.
In the 2030s, the Boy Detectives Club operates under Kogorou Akechi, a brilliant but enigmatic investigator who leads a team of gifted young detectives through cases that push the boundaries of reason. When Kensuke Hanazaki encounters Yoshio Kobayashi, a boy cursed with immortality by a phenomenon called the Unidentifiable Mist, his solitary existence fractures. Yoshio desperately seeks an end to his endless life, but Hanazaki sees something valuable in him and extends an invitation to join the club. As Yoshio reluctantly integrates into the group, their investigations take a sinister turn. A shadow looms over their cases: the Fiend With Twenty Faces, a legendary criminal mastermind whose presence connects to the very fabric of their world and Akechi's mysterious past. What begins as a refuge for a lonely immortal boy becomes something far darker, where each mystery peels back layers of a conspiracy that threatens to unravel everything they believe about their detective leader. Trust becomes currency, and secrets accumulate like evidence at a crime scene.