Wakoku
Wakoku was the name used by early China and its neighboring states to refer to what is now known as Japan. There are different ideas about how much power the early kings of Japan had.
According to ancient Chinese books like the Book of Sui and the History of the Northern Dynasties, the borders of Japan were described as being five months from east to west and three months from north to south.
The Wajin, who were people from Japan, were mentioned in historical documents like the Book of Han and the Geographical Survey of Japan, dating back to around the 2nd century BC.
In the late 7th century, the Yamato kingdom, which was also known as Yamato, changed its external name to Japan, but its relation to Japan mentioned in the Book of the Later Han is not clear. There are differences in the descriptions found in the Old Book of Tang and the New Book of Tang.