Naruto Goes Back In Time:
Naruto (Canon) by Masashi Kishimoto
Chapter 1: God Tree (Prologue)
Kayuga Otsutsuki was from the clan Otsutsuki, and mother to Hagoromo and Hamura, they both lived in an era before the villages where born—back when the human race was at constar war, one after another. This was called the shinobi war. There was a forbidden rule that no one shall eat from the God Tree because it can give and incredible source of power, a power so vast that it would take decades to control, that was indeed the mother of chakra (both physical and spiritual aspects would need be trained in). Out of the tree came a fruit and that fruit was in fact a source of this power called chakra. She had disobeyed this ruled to end the endless wars of mankind, and thus as a result she was worshipped as the Rabbit Goddess. However, time came by and this power corrupted her, until, that is she had two sons Hagoromo (the sage of six paths) and Hamura (his younger brother). They both gained something from birth that is to say that they were the first humans to be born with chakra. And so their training was to be exceptional in order to master this power. However, time went by, and soon Kaguya started to hate human kind, they had isolated her, for fear of this power, and no later they started calling her a demon. That is what the human race came to be. However, as for Hagoromo and Hamura, there was a way to defeat their mother, something called seals. The light (yang), and the shadow, seal (yang). Kaguya's ideology soon became dangerous, it was to trap everybody in a infinite tsukiyomi, that is an illusion - coming from the the moon by using both the sharingan and rinnegan powers, to cast the ultimate illusion. This however, was stopped when she later learned that the god tree was coming out of control because of her disobience and thus it transformed into the ten tails, a beast so powerful it can destroy mountains, with at swing of its tail, and change the landscape with sheer force…
Hagoromo Otsutsuki and his brother Hamura, were both legends, the elder soon became the legendary god-like figure who was known as the sage of six paths (the Rikudo Sennin). They had fought countless battles, in order to prepare to fight against the Ten –tails. They succeed and Hagoromo being the elder brother sooner became the first jinchuuriki, that is the first human sacrifice. Usually the tailed beasts are sealed one way or another into the stomach of the human, each one having a unique seal.
Years later, after, becoming the first jinchuuriki, Hagoromo decided to be a Sage, and travel the rest of the world. He was later known as the founder of Ninshu, that is to say Ninjutsu. For certain techniques each person had different sources of chakra, that is to say wind, water, earth, or fire. And each of these applied to certain hand signs. In order for them to do a justu you would not only have to control chakra, but control the hand signs perfectly, and have perfect control of your chakra (along with your chakra affinity). That is what Ninshu was all about. However, there were other areas for a shinobi (ninja)—that should master, for instance, kenjutsu (the art of the sword), medical ninjutsu (chakra control) handsings (for certain jutsu), and finally chakra nature, (along with shape and manipulation. He became the founder of the shinobi arts.
Hagoromo, years, later, had two sons, the elder brother named Indra (who inherited his father eye techniques both sharingan and rinnegan) and the Asura, who later, became and un-awakened genius, and soon caught up to his elder brother with physical techniques. Chakra is both physical and spiritual, both handsings bringin the chakra from deep within your body and then release it outwardly. However, Hagoromo had to choose a heir, one that would inherit the name Otsutsuki, he sought originally that his elder son would inherit his power, but he had a vision that soon just like his mother, the power would soon corrupt him. And thus, he chose the youngest one, Asura, to be heir of the Otsutsuki, jealousy of not being the chosen one, Indra, has sought his brother for a battle, to see whether he would inherit his fathers inheritance.
Asura won the fated battle and had left his brother alive. Thus came to the conclusion of the shinobi clan wars. The more powerful clans in the era, where the Uchiha clan, and the Senju clan. These clans were eternal rivals, and were fated until two shinobis came, one being called Madara Uchiha, and the other called, Hashirama Senju.