He has a tall, lean build, pale blonde hair, sharp brown eyes, pale skin and a serious expression. He wears a red trench coat and wears his Future Foundation ID on his left shoulder. Sonosuke wears dark red fingerless gloves, baggy black pants, and dark brown boots. He carries a multitude of weapons hidden in his coat. Sonosuke is stated to be a "silent type", who avoids talking to others, the only exception being his romantic partner Ruruka. He is incredibly loyal and very protective of her.