Ren is a tall young man of slim to athletic build. He has a pale complexion with unkempt, wavy black hair that falls over his eyes. His eyes are gray. Despite his messy hair and slouched posture, he wears all of his clothes primly and properly, he wears a set of large black glasses and his winter school uniform, which consists of a red-buttoned black blazer with Shujin's emblem on the pocket, a white turtleneck shirt with chevron detailing on the collar and slim red pants with a plaid pattern.