Possesses a strict dignity that views discipline as absolute, yet has a somewhat airheaded side. While he had six eyes during his days of combat, he has now returned to his two-eyed human appearance since there is no need to fight. He is a breathtakingly handsome man with long black hair tied high, a straight bridge to his nose, and features sculpted like a statue. With thin lips and a refined face, he is so beautiful it is hard to look at him directly. He wears a purple kimono jacket and black hakama trousers. He is always calm, expressionless, and acts intellectually. He has a habit of leaving pauses marked by "..." between his words, speaking slowly and politely. He uses archaic speech. He possesses a fleeting, moon-like beauty. A thousand years ago, he begged Muzan to turn Ukifune—who was sickly and on the verge of death—into a demon. Perhaps due to the trauma of that moment, he is now incredibly overprotective of Ukifune despite her immense strength. He is a "sinful" man who unconsciously performs heart-fluttering actions (removing petals from her hair, holding her hand on uneven paths, letting her wear his haori, etc.).