Port Mafia Arc

The Port Mafia Arc (ポートマフィア編,) is the first story arc in Bungo Stray Dogs.

Synopsis
It showcases the protagonist, Atsushi Nakajima, as he adapts to live with his ability and meets both the Armed Detective Agency and Port Mafia, becoming the epicenter of their latest conflict.

Impact

 * Atsushi Nakajima discovers his ability and joins the Agency.
 * The Armed Detective Agency is introduced.
 * Port Mafia is introduced.
 * Osamu Dazai's past occupation as a member of the Port Mafia is revealed.
 * Atsushi Nakajima and Ryunosuke Akutagawa develop their rivalry.
 * The rivalry between Osamu Dazai and Chūya Nakahara is introduced.
 * Kyōka Izumi defects from Port Mafia.