For weeks, the orphanage of Atsushi Nakajima has been haunted by a mysterious tiger that he appears oblivious to. Believed responsible for the odd happenings, the 18‑year‑old is suddenly expelled, left destitute and aimless in a city that never sleeps and its surrounding suburbs.
While starving beside a riverbank, Atsushi rescues an eccentric figure named Osamu Dazai from drowning. A whimsical suicide aficionado and supernatural sleuth, Dazai has been probing the same tiger that tormented the boy. Together with his partner Doppo Kunikida, they crack the case, yet its outcome traps Atsushi in a precarious position. As strange incidents unfold during this chaotic period, he is forced to join their supernatural investigation firm, tackling bizarre assignments beyond police reach alongside a host of enigmatic colleagues in the shadows.
