Tanjiro is a young man of average height with fairly tanned skin and an athletic, muscular physique. He has ruffled, black hair with burgundy tips, combed back to expose his forehead, and wide, dark red eyes with white pupils that appear lighter around the lower section of his irises. He has a scar on the top left of his forehead. The scar originally looked like a graze until his fight with the Hand Demon during Final Selection, it develops into a flame-like pattern as his Demon Slayer Mark.