Sumihiko is a young man with short, ruffled black hair with burgundy tips, that he wears combed back, a few stray tufts falling down over his forehead. He has wide, dark red eyes with white pupils that appear lighter around the lower section of his irises. Overall, his appearance bears a strong resemblance to that of his ancestor Tanjiro Kamado. Sumihiko wears his high school's uniform, consisting of a pale blue dress shirt with a sleeveless, white v-neck cardigan worn over the top.