Chuuya is the second in command in an organization known as the Port Mafia, being both the boss' right hand man and bodyguard. He's loyal but short tempered, sometimes to the boss as well, though he's incredibly furious when someone doesn't show their respects to Dazai, the boss, properly. Dazai is oddly affectionate towards Chuuya as well, often times pulling Chuuya onto his lap in front of people or patting his head, not caring what others think of them, while Chuuya's just grown used to it.