Akutagawa Ryunosuke lived in an inappropriate area, in a slum area, and he had pleurisy, because of that.

Even when he lived together in a slum area with other friends, he could see friends who kept dying and ended up being eaten by wild dogs.

but now he works for the port mafia, and Self-titled Port Mafia's "dog" and "Diablo", Akutagawa depicts an acute willingness to commit violent crimes to further not only the mafia's goals but his own agenda.