Chūya Nakahara (中なか原はら 中ちゅう也や, Nakahara Chūya?) 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. His ability, Upon the Tainted Sorrow (汚よごれっちまった悲かなしみに, Yogorecchimatta Kanashimi ni?), revolves around gravity-manipulation, allowing him to manipulate and make gravitons, as well as alter the gravity of anything he touches. He can walk and stand on ceilings.