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.
この時代の貿易は遣唐使に付随して行われる朝貢貿易（朝貢に対する回賜・購入）が主であったが、必ずしも民間の交易船が存在しなかったことを意味するものではない。