Gyutaro was one of the primary antagonists in the Entertainment District Arc of Demon Slayer: Kimetsu no Yaiba. He was a demon affiliated with the Twelve Kizuki, holding the position of Upper Rank, a position he shared with his younger sister, Daki.
Over a century ago, Gyutaro was a human who worked as a debt collector in the Rashomon Riverbank of Yoshiwara, the lowest class in the Entertainment District, before he and Daki were turned into demons by Doma.