For weeks, the mystical tiger has been plaguing Atsushi Nakajima's orphanage, yet he is completely oblivious to its existence. Unfortunately, the blame for the strange occurrences falls on Atsushi and he is immediately kicked out of the facility, leaving him destitute, hungry, and lost in the bustling city. Starving and weak, Atsushi finds himself on a riverbank stumbling upon a strange man by the name of Osamu Dazai, who is on the verge of drowning. Dazai is a peculiar character, fascinated with suicide and paranormal investigations. Surprisingly, he has been tracking the same mystical tiger that has been terrorizing the boy. Atsushi joins forces with Dazai and Doppo Kunikida, and they begin to investigate the case. However, the outcome of their investigation puts Atsushi in a dangerous situation. As more bizarre incidents start to occur, Atsushi is sucked into the world of paranormal investigations and is forced to work with a group of mysterious detectives on cases that the police cannot handle. His enigmatic colleagues and the surreal circumstances will challenge him beyond anything he has ever experienced.