In the bustling, supernatural-infused city of Yokohama, Atsushi Nakajima is an orphaned outcast haunted by a mysterious, transformative curse. After being expelled from his orphanage, he is on the verge of starvation until he encounters Osamu Dazai, a whimsical yet enigmatic detective with a penchant for dramatic suicide attempts. Dazai belongs to the Armed
Detective Agency, a specialized group of individuals gifted with unique supernatural abilities who handle cases too dangerous for the police or military. Dazai reveals that Atsushi is a "were-tiger," a powerful entity pursued by the notorious Port Mafia, a ruthless criminal syndicate that controls the city’s underworld.As Atsushi joins the agency, he struggles with his self-worth and the terrifying power he cannot fully control. He learns that the city is a powder keg of warring ideologies. The Armed Detective Agency, led by the stoic Yukichi Fukuzawa, operates as a moral bulwark against the darkness, while the Port Mafia, commanded by the cold and calculating Mori Ogai, seeks to consolidate power through violence and intimidation. The conflict intensifies with the introduction of the Guild, a wealthy, American-led organization of ability-users aiming to seize Yokohama for their own grand design.The narrative evolves into a high-stakes chess match where the lines between hero and villain blur. Characters like the fanatical Ryunosuke Akutagawa, driven by a desperate need for Dazai’s validation, and the tormented Kyoka Izumi, who seeks redemption after a life as a mafia assassin, illustrate the series' core theme: the
search for meaning within a fractured existence. As the stakes escalate to global threats and cosmic conspiracies, the protagonists must confront their past traumas and the heavy burden of their powers. Through shifting alliances, philosophical debates on justice, and visceral, stylized combat, the story examines whether those who have been cast aside by society can ever truly deserve to belong. Ultimately, the series is a character-driven saga about finding a reason to live in a world that often demands death, forcing its cast to decide if they will be defined by their destructive origins or by the bonds they forge in the line of duty.