Sasuke Sarutobi, one of the heroes of ninjutsu, was created in Tachikawa literature at the end of the meiji period. Up until that time, the general image of ninjutsu was related to black arts, witchcraft, magic, hobgoblins, thieves, and assassins. Sasuke was a mischievous boy. Books describe him as an innocent child with a strong sense of justice. In the stories, great importance was placed on humor, with actual combat considered secondary.
One day, Sasuke said to himself, "I’m already ten years old. It’s no longer practical for me to practice yatoo (a form of Kiai-spirit shout) with monkeys and deer. I’ll follow my father’s advice and seek a master swordsman to train me. I’m going to go to Okunoin in the Torie Pass to ask the gods to provide me with a good master."
When Sasuke arrived at Okunoin, he began playing among the clumps of trees rather than practicing yatto. Not satisfied with a stick, Sasuke grappled with a large tree, trying to twist is down. Then, he heard someone laughing at him. Sasuke called, "Hey, who are you? I’m concentrating on fencing. Don’t you dare laugh at me. Come out here. I’ll not forgive you." As he looked around, he saw an old man with swept-back long hair tied at the back of his head smiling at him. The man’s hair was as white as snow. Sasuke asked, "Oh, you laughed at me, didn’t you, old man?"
The old man answered, "Yes I did."
Sasuke asked him again fiercely, "Why did you laugh at me? Answer me. If there is no good reason, I’ll never forgive you even if you are an old man."
The old man laughed and said, "Well, Sasuke, you were practicing with a tree, but this is like practicing with a dead enemy. You can’t improve your fencing that way. Do you want to learn fencing so badly?"
This was the age of civil wars, and only a few people could live to an old age. Therefore, Sasuke reasoned, an elderly fencing instructor was surely a master at martial arts.
Sasuke said, "Old man, are you a master of martial arts? I want to learn the secrets of martial arts."
"What are you going to do with them, after you learn them?"
"I’ll be a strong swordsman and win fame and honor."
"Wonderful. What an admirable goal for only a boy! All right. I’m going to five you a lesson in consideration of your zeal and determination."
Sasuke prostrated himself before the old man and thanked him. Then, Sasuke delivered a sword stroke to the old man. However, he had disappeared. Sasuke looked around nervously. Then, he was suddenly tripped by an attack from behind and fell flat on his face. The old man appeared suddenly in front of Sasuke with a smile.
The old man taught Sasuke for the next three years. He tried to teach him the godan or fifth-level secrets by saying, "Don’t you have your eyes in your back? How handicapped you are!
"You’ll be a failure unless you know how to defend your weak point, even if you know the unguarded point of your opponent. The secret of defense in martial arts is to always be alert.
"Unless one knows his own weak point, he can never be certain that the weak point of his opponent is not a decoy."
In addition to ankokutoshijutsu techniques for seeing in the dark, Sasuke learned to listen for stealthy footsteps coming from more than thirty meters away.
One day the old man handed a scroll to Sasuke and said to him, "Well, Sasuke, this is my parting gift, the rules of Ninjutsu. Carry it with you for life and behave prudently. When you are in combat with others or meet heroes and great men, you’ll never be beaten if you understand what is written in this scroll."
When the old man gave the scroll to Sasuke, he for the first time revealed his name as Hakuunsai Tozawa, and then disappeared.
Sarutobi Sasuke was a famous ninja featured in many Japanese children's stories from 1911 to 1925. His name was also used in Naruto, Sarutobi Asuma and Uchiha Sasuke (the Sandaime Hokage is also called Sarutobi).
It is a matter of dispute whether he was real, or a fictional creation of the Meiji era. He is commonly listed as one of the ten retainers of Sanada Yukimura.
'Sarutobi' is written with two Kanji (adapted Chinese characters), 'saru' the character for 'monkey', and 'tobi' the character for 'jump'. He was known for his monkey-like agility and quickness, especially in trees. Many depictions of him in Japanese pop culture portray him as having been orphaned and raised by a band of monkeys, therefore giving rise to the monkey-like abilities.