Genya is a foul-mouthed and ill-tempered individual; a "lone wolf" who refuses any help from others and does not show any interest in being polite or having any manners, much like his older brother. During the Final Selection, he roughly handles Kanata Ubuyashiki, grabbing her by her hair and yelling at her even though she is a child. He becomes more open to cooperation during the battle against Hantengu, an Upper Moon demon, where he works alongside Tanjiro, Mitsuri Kanroji, and Nezuko Kamado. Sanemi's refusal to acknowledge him also makes Genya insecure as he comes to realize just how weak he is compared to his companions. Nonetheless, he does whatever he can to help his allies, even if it gets him horribly maimed in the process.