Nittoboeki (trade between Japan and Tang dynasty China) (日唐貿易)
Nittoboeki (日唐貿易) is the trade that was carried on between Japan and Tang dynasty China.
Although the trading at that time was mainly the tribute trade (tribute, and gift returns, purchases to conform it) along with the dispatch of Japanese envoy to the Tang Dynasty China, it does not mean that there were no private trading ships. For instance, there is a definition about the nation's right of preemption in the trading between Japan and gaiban (derogatory expression of foreign countries and foreigners) in Genshi Ryo (regulations of markets and checking stations) of Yoro-ryo (Yoro Code). It is said that the private trade relationship came to exist in the late Nara period at the latest, and also the trade relationship that relayed Shiragi (ancient Korean kingdom) and Bo Hai seems to have existed. The existence of these Shiragi merchants, Jang Bogo and 金珍, who helped Ennin trying to do Nitto Guho (travelling the Tang for seeking the teaching of Buddhism), was known in history. They engaged in the trade between Japan, Shiragi and Tang. An episode that a monk in Tang sent a letter addressed to Michizane by a Shiragi merchant, has been also written in the proposal for stopping Japanese envoys to Tang Dynasty China ("Kanke bunso" [an anthology of Chinese-style poetry by SUGAWARA no Michizane]) that reported to the Imperial Court by SUGAWARA no Michizane. Today, many potteries, the flagship product of karamono (things imported from China) that time have been excavated from the remains of Heiankyo, and many think that although the number of the Japanese envoys to Tang Dynasty China declined, and even after the transfer of national capital to the city of Heiankyo, many potteries were brought from China into Japan and many of those were brought by private merchants.
When a vessel with foreigners such as envoys and merchants arrived at Kyushu, Dazaifu (local government office in Kyushu region) reported the Imperial Court about it and the Imperial Court ordered Dazaifu to stop the foreigners and give them warm welcome in the facilities such as Korokan at Hakatanotsu, Kyushu. The nation's right of preemption was asserted by the Imperial Court by either sending people, such as benkan (officials of the dajokan) or kurodo (Chamberlain), assigned to serve as karamono no tsukai (Supervisor of Chinese goods) to the ports of call, or by the government officials (esp. ones of low to medium rank) directly negotiating and purchasing from the merchants based on the detailed list of necessary goods made by the Imperial Court. However, those aristocrats with the information about the foreign merchants often ordered their servants or related merchants to reach out them, and traded with before Dazaifu. Although the Imperial Court issued the prohibition against these kinds of acts that violate the nation's right of preemption, it did not have much effect on it since many of the aristocrats who enacted the prohibition could not curb the desire for karamono, and violated the prohibition by themselves. Later, trading posts were built up by the merchants from Tang and Shiragi in the northern shore area of Kyushu centering on Hakatanotsu. The regulators such as the government officials at Dazaifu also participated in this kind of trading. FUNYA no Miyatamaro, Chikuzen no kami (governor of Chikuzen Province), who built up contact with Jang Bogo was a major example of them.
The fact that silver, textile fabrics, cloths and threads were brought to Tang Dynasty from Japan as tribute, and textile fabrics, spices, medicines, Buddhist objects, scriptures and books were brought into Japan from Tang, is seen in records as ones written by the Japanese envoys to Tang Dynasty China. Also, there were goods from Central and Western Asia that had relayed the Silk Road. Some of the karamono that were brought into Japan can be assumed from the treasures in Todaiji Temple Shosoin or "Nihonkoku genzaisho mokuroku" (Catalogue of Present Books in Japan).