Chūya Nakahara/Relationships

Osamu Dazai
Dazai is Chūya's former partner back when Dazai was still a member of the Port Mafia. The pair make-up Double Black, or otherwise known as "Soukaku." The two harness a deep relationship with lots of history, involving their childhood. Both know each other well enough to know the way the other thinks, acts, and fights. The two regularly say that they "hate" each other and argue. It's also known that Chūya trusts Dazai.