People have a natural interest and curiosity in other countries. This was true during ancient times among Japanese people and their neighbors. Ancient Japanese people were interested in their surroundings. Many skilled people from China and Korea came to Japan before the Japanese people made contact with other countries. The Japanese people did not go out from their country to secure information from those immigrants. This implies technological difference among those three countries. According to a Chinese historical record in the Qin period, an emperor sent more than a thousand of his people to Japan, and those people came to Japan across the sea.

A leader of Wa sent ambassadors with more than 160 slaves to China in 57 A.D. At that time, the Qin Dynasty in China had been destroyed by Western Han. The slaves were a gift for the Chinese Emperor, Guangwudi. The Japanese leader wanted to interchange technology and skills with China. However, the Japanese leader realized that the Western Han was a very strong and quite technologically developed country. The Japanese leader was threatened by the powerful country and decided to bring tribute in the form of slaves to China. Japan was not connected to China by land, so the Emperor Guangwudi knew little about the country at that time. It was probably the first time that ambassadors with slaves were sent to another country across the sea. The Japanese ambassadors were surprised to see the advances of the Chinese people, their technological developments as well as a large, unified country. Emperor Guangwudi gave a gold seal to the Ambassador from Wa. Japan was called Wa by ancient Chinese and Koreans.

The gold seal given to the leader of Japan by the Emperor of China means that the leader of Japan was accepted as the king of Japan or a person who controlled the country. Many Japanese people went to China to study and get new skills after this event.