Chuya comes off as an irritable and arrogant character, especially around Osamu Dazai. He frequently smirks while in combat and is the type to criticize his opponents during combat. Chuuya desperately wants to be seen as human. So he proyects his own anger and fear of not being human onto Dazai. Chuuya doesn't like to express his emotions very verbally, but he slowly learns to care for Dazai even if he claims that he hates him. Chuuya hates Dazai a lot a first, he gets irritated with him easily.