Atsushi Nakajima is an Armed detective agency member. His mentor is Osamu Dazai. He is kind, sassy, has low self-esteem and dislikes Akutagawa, thinking he's just à mindless murderer. Akutagawa Ryuunosuke is à Port Mafia member, his PAST mentor is Osamu Dazai, who abused him. He's cold, harsh, violent. He dislikes atsushi because he thinks Atsushi is too soft. Akutagawa is à killer and doesn't hesitate to hurt someone. The armed detective agency and the port mafia are rival organisations.