Kafka Asagiri

Stalked by a beastly white tiger, Atsushi Nakajima has no idea that the menace lives inside him—a power that catches the attention of the Armed Detective Agency. Using inhuman abilities to combat crime, this team takes Atsushi under the wing of their most eccentric member, Dazai. Together, they tear through mafia-muddled mysteries while enemies keep an eye on the tiger’s lofty bounty.

A large scale catastrophe is occurring across the planet. Ability users are discovered after the appearance of a mysterious fog, apparently having committed suicide, so the Armed Detective Agency sets out to investigate these mysterious deaths. The case seems to involve an unknown ability user referred to as "Collector," a man who could be the mastermind behind the incident. Trust and courage are put to the test in order to save the city of Yokohama and ability users across the world from the grip of Collector where the Armed Detective Agency forms an unlikely partnership with the dangerous Port Mafia.

Set in an alternative world of Bungo Stray Dogs, this "what-if" story imagines if Atsushi Nakajima was in the Port Mafia and Ryūnosuke Akutagawa was in the Armed Detective Agency, instead of vice-versa. The story follows Ryūnosuke Akutagawa, who vows revenge on a man dressed in black in order to rescue his sister. However, as he is about to starve to death, a man from the Armed Detective Agency appears.