My take on the storyline from a Gaioh perspective ninja (short version)
Hidden in the hills of a forgotten Gaian land, lay the Gaioh clan. For centuries, their civilization lived in peace, teaching the ways of Ounagi and AsuKikingu to the future generations.
Their peace was suddenly shattered when a neighboring and once peaceful village incited what would be known as "The day of Meiji Ounagi". It went down in legend that the leader of the now hostile village was wrapped in cloths of the Chyaku Norisu- an item fabled to have been gained through unspeakable acts of Gaian sacrifice, while being passed off as a sign from the great Chayaku Norisu it was now time to reign supreme over Gaia.
The remaining Gaioh clan abandoned their once thriving land, retreating and scattering throughout Gaia into even smaller clans. With a promise of protecting the future and gathering once more, this was known as the "Great Gaioh Divide".
The Gaiohs mission of avenging the wrongs by the now well-recognized Norisu clan stayed constant throughout each of the groups. Over time, that definition broadened, as the Gaiohs became known for helping others in need. Some groups taught their children to attain the ultimate symbol of the clan, the Ninja Headband. Others taught it was more important to hide the Gaioh identity until the Day of Gathering: for when the Gaioh clan would make the pilgrimage centuries later back to the homeland and be so strong in number the Norisu would have no choice but to surrender.
(just a thought on background 3nodding )