Chuuya Nakahara is a member of the Port Mafia as well as Dazai's former partner in Twin Dark. He is one of the five Executives in the Port Mafia. He has the Ability named Upon the Tainted Sorrow. On the surface, he is a temperamental and rather arrogant, blunt man. He revels in fighting, happy to show off his combative ability, and taking great pride in his reputation as the mafia's strongest martial artist.