The first Emperor of Japan was a self proclaimed grandson of the sun goddess Amaterasu. He was part of the Yamato Clan who lived on the island of Honshu. By 500 A.D they controlled most of the island. Even though they didn't control all of Japan they called themselves the rulers. Other clans eventually gained power over the Yamato clan and used their ruler like a puppet.
In 794 A.D Japan moved its captial to Henian now called Kyoto. Many of the nobles moved there and they developed Chinese Culture. The women of the Dynasty could learn to read and write Japanese because they weren't allowed to learn Chinese. They made some of the best books for the time. Unfortunately, with lack of food production and the growing population they Dynasty started to go downhill.