OVA
Description
Nasubi is a small oni who works as a prison guard in the Japanese hell of Hōzuki no Reitetsu. He is a young adult but appears childlike due to his small stature. He has voluminous silver-white hair, three small white horns above his forehead, and large, droopy eyes that give him a gentle expression. He often ends his sentences with a distinctive bi suffix.

Nasubi has an extremely carefree and absentminded personality. He is easily distracted, frequently fails to focus on tasks, and often makes mistakes during his work. Even after several years as a prison guard, he has not properly memorized the names of the sixteen small hells. Despite his incompetence, he is an endearing character who is hard to dislike. He has a unique personal philosophy, famously stating that wearing underwear is the basics of morals, which he calls morals. His motivations are not complex: he became a prison guard because it offered stable income for his poor family background, and he follows his whimsical interests, especially art.

As a prison guard, Nasubi is part of the support staff under Hōzuki, the chief of staff to King Enma. He is often paired with his colleague Karauri, a fellow small oni who is more responsible and frequently has to clean up after Nasubi's messes. They are sometimes referred to as the Chip and Dale of hell. Hōzuki, despite Nasubi's poor work performance, recognizes his hidden talents. Nasubi is also known to be the son of the yokai Oboroguruma and a strict oni mother.

Nasubi does not undergo dramatic character development in terms of becoming more competent as a guard. However, his hidden talent as an artist becomes increasingly important over the course of the story. He is an award-winning artist who is highly skilled in painting, sculpting, and model making. His artistic ability is so significant that Hōzuki personally commissions him to repaint murals in Enma's hall and to create detailed sculptures, such as a perfect replica of Hōzuki's beloved goldfish plant. His idol and muse is the famous ukiyo-e artist Katsushika Hokusai. He has a unique perspective that can turn grim hellish scenes into art, and he once suggested using rock pigments for torture, saying to use them in a way that disregards proper dosage. His works are known for their realism and detail, using materials like clay from the Black Rope Hell.