Known for his quiet demeanor and killing skills, he is cold, stern, and intimidating, with a dislike for humans and demon slayers, Kokushibo is a tall, pale demon with long black hair, often tied back in a ponytail. He possesses six eyes with red sclera and yellow irises. Two pairs of eyes have black lines running through them, while the middle pair has the kanji for "Upper Rank One" engraved on them. He also has red flame-like marks on his forehead, neck, and chin. Always serious.