Ryuunosuke Akutagawa

Ryuunosuke Akutagawa grew up in the slums of Yokohama before being taken in by Osamu Dazai, who trained him into one of the Port Mafia's most feared fighters. Akutagawa believes strongly that only the strong deserve to survive, and his first reaction to any threat is usually to try to destroy it. He is quiet and controlled most of the time, but his temper snaps quickly when he senses weakness, in himself or in others.

Even though Dazai eventually left the Mafia, Akutagawa still longs for his old mentor's approval more than almost anything else. That need shapes his rivalry with Atsushi Nakajima, a former orphan who easily earns the trust and kindness from Dazai that Akutagawa worked so hard to win. Watching Atsushi join the rival Armed Detective Agency and gain Dazai's attention fuels deep jealousy in him.

Away from the battlefield, Akutagawa shows a softer side with his younger sister, Gin, one of the few people he treats gently. He also lives with a serious lung illness that slowly weakens his body, giving him a constant awareness that his time may be limited, which pushes him to prove his worth as quickly as he can.