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.
橋本祥平
as Ryunosuke Akutagawa
鳥越裕貴
as Atsushi Nakajima
Rui Tabuchi
as Osamu Dazai
谷口賢志
as Sakunosuke Oda
紺野彩夏
as Gin
Teruma
as Kunikida Doppo
Nagae Ryoki
as Ranpo Edogawa
桑野晃輔
as Junichirō Tanizaki
Hitoshi Horinouchi
as Kenji Miyazawa
Ao Hirokawa
as Akiko Yosano
Akari Saito
as Naomi Tanizaki
桑江咲菜
as Kyouka Izumi
