"The Crimson Shadow" is the epithet for this jet-black haired man. Rokuro is a shinobi or spy who serves the daimyo named Yoshimasa. He is the last person left in his clan, who died due to the massacre by the enemy clan. Rokuro is very proficient in survival skills, stealth attacks, toxicology, and medical. In his daily life he does not appear as shinobi so that people won't know about his real job, he disguises himself as a monk and helps every sick locals. He is usually accompanied by a female ninja named Ayaka, both as a monk and shinobi in act. Later, Rokuro will establish a good relationship with Shin and friends. Rokuro is smart, conscientious, silent, and rarely shows any expression. His meeting with Shin and friends certainly changes the path of his life... There is a time when he will awaken memories of the dark past...