Bungo Stray Dogs manga volume 20 features story by Kafka Asagiri and art by Sango Harukawa.

One member of the Decay of the Angel stands in the way—Fukuchi Ouchi. Atsushi and Akutagawa have beaten powerful enemies before, but can they work together to defeat the living legend known as the strongest skill user...?! The man known as Fukuchi, veteran of innumerable battles and who once trained alongside President Fukuzawa, draws his sword!