So I've been working on the first few chapters of my fanfiction. It was slow at first but I'm making progress. I hope to put a few excerpts up once I edit the chapters more. However, I did write up a brief summary of the series history. Enjoy and ask questions if you want.
Centuries before the main story line, the world was plagued by a terrible demonic force know as Jubi, the ten-tailed demon. This beast held the very elements of pain, disaster and destruction at it’s beck and call. Since before written history, this demon brought devastation where even and when ever it surfaces. It was not until a man known only as the Rikudō Sennin, or Sage of the Six Paths fought against the horrid beast and sealed it within himself, becoming the first jinchūriki (Demon host), and bring peace to the Shinobi world. Due to this feat, as well as his almost god-like power and abilities, the Sage would later be known as the God of Shinobi.
Sometime after sealing the Ten tails inside of him, the Sage had to sons. The Sages ultimate desire was to establish peace through out the land, as his end was vastly approaching, he entrusted his strength, dream, and legacy to his two sons. The older son, who inherited the Sage's "eyes" (his powerful chakra and spiritual energy), believed that power was the true key to peace. The younger son, who inherited the Sage's "body" (his powerful will and physical energy), believed that love was the true key to peace. On his deathbed, the Sage chose his younger son to be his successor.
Before his death, the Sage realized that the seal on the ten-tails would not hold once he dies. Aware of this, the Sage used his ability known as “Creation of All Things” to divide the Ten-Tails' chakra into nine parts, which would become known as the tailed beasts. He then used Chibaku Tensei to seal the Ten-Tails' body inside a gigantic stone prison in the sky, thus creating the moon. Right before his death, the Sage told the nine bijuus (tailed beasts) that they would always be together even when separated, and that one day they would become one entity again with different names as well as forms than they did then when the time came for them to understand what true power was.
After the Sage’s death, and due to his bitterness and envy that his birthright was denied to him, the older son attacked the younger, beginning a war between them. Their feud would continue on through their descendants: the Senju clan and the Uchiha clan, who were the two most powerful family clans in the shinobi world. For centuries after that, the world was in constant war for power and territory. Countries would hired ninja families as mercenaries, with the Senju’s and Uchiha’s always being on opposing sides. It was not until Hashirama Senju and Madara Uchiha made agreed to a peace treaty and worked together with there families to create the first ninja village, Konohagakure (Village Hidden in the Leaves). Soon, other countries followed suit, creating the one hidden village per country system that still exist in the modern shin obi world.