A member of the Sanada ninjas and the youngest among the ten.
His father, a former Koga ninja, died when Sasuke was a child. He was raised by Hakuunsai Tozawa to become a Sanada ninja. He later serves Nobushige Sanada in intelligence and protection work. He blames himself for the assassination of Masayuki. Despite being the youngest, he is the most skilled in ninja arts. True to his name, he excels at monkey-style ninja arts and is friends with a little monkey.