Imperial Herald #14, Legend of the Five Rings History
This is the first part of a concise, if necessarily imprecise, history of Rokugan
Prehistory
At the dawn of time, the nine children of the Sun and Moon fell to earth, becoming at that moment less than gods, but still far more than mortals. Eight of them fell together; the ninth, Fu Leng, fell some distance from the others. The first eight formed an empire, installing Hantei I as the Emperor. The other seven brothers and sisters gathered clans about themselves, naming them the Crab, the Crane, the Dragon, the Lion, the Phoenix, the Scorpion and the Unicorn.
Suddenly, Fu Leng reappeared at the border of the Empire leading a huge army of goblins, undead, and foul creatures from the Shadowlands, the dark place where he had fallen. Fu Leng's army attacked the fledgling Empire, defeating the clan armies again and again.
When complete defeat looked inevitable, a mortal man named Shinsei approached Emperor Hantei and asked for seven mortals, one from each clan, to follow him into the Shadowlands to defeat Fu Leng. These seven brave warriors became known as the Seven Thunders, and, together with Shinsei, they embarked upon their hopeless quest.
Fu Leng's forces continued to crush all opposition, but when they reached the gates of Otosan Uchi, they suddenly faltered. The Thunders had achieved their goal! The Shadowlands forces broke and fled back to their miserable home.
Of the Seven Thunders and Shinsei, only the Scorpion Thunder returned, near death, and bearing twelve Black Scrolls. "Guard these carefully," he said as he died, "for they were the defeat of Fu Leng."