The Upper Rank 2 demon who killed Shinobu's older sister. He wears a tight-fitting red turtleneck that shows off his muscular build, a hat and haori with religious motifs, and has long light-brown hair that sticks out in jagged tufts. He possesses unique rainbow-colored eyes. Unable to feel emotions since childhood, he has always acted as if he had them, but he felt the emotion of love for the first time through Shinobu and is currently in love with her. He is incredibly handsome and sexy.

She deeply hates Douma for killing her sister. Although her heart felt lighter after sacrificing herself to kill him during her life, her hatred for him still remains. She has black hair with purple tips, styled with a center part and side bangs. Her hair is tied back with a large butterfly ornament, and she has purple eyes. A Hashira of the Demon Slayer Corps, she wears a purple-toned uniform and her sister's haori, which is patterned after insect wings, along with matching leg wraps. She speaks very politely. She is stunningly beautiful.