The is an object dating to 1584 preserved at the Yamaguchi Prefectural Archives that has been designated an Important Cultural Property of Japan due to its historical significance and the light it shines on trade and relations between Momoyama Japan and Ming China. Background In 1371, in an attempt to prevent opponents joining forces with the wakō, the Hongwu Emperor, founder of the Ming, issued a maritime prohibition on private overseas voyages and commerce. Foreign merchants sailing to China for trade were also banned, communication with anyone defying this ban was punishable by death. In 1383, a trade tally system was then introduced to facilitate tributary missions from foreign powers. The last of the Japanese missions to Tang China occurred in the ninth century, and several more recent attempts to establish diplomatic relations with the Ming had been rebuffed. But a Hakata merchant named returned from China and told Ashikaga Yoshimitsu of the profits that could be made through trade with the Great Ming. In Ōei 8 (1401), the Ashikaga shogunate dispatched the first of the Japanese missions to Ming China. They carried with a "tribute" of gold, horses, and swords, as well as a number of Chinese castaways for repatriation. The mission was headed, like those that followed, by a Zen monk from the Five Mountains in Kyōto; Koitsumi served as vice-ambassador. This mission "marked the re-opening of trade relations" between Muromachi Japan and Ming China. The second mission, headed by Kenchū Keimitsu, set off for China in 1403; when it returned the following year, it did so with an envoy from the Ming and 100 Yongle tallies: "this marks the beginning of the , the 1404 mission the first to implement this system. While the Ming government would make official purchases, the Japanese envoys and accompanying merchants were permitted to conduct private trade with licensed counterparts. Ningbo was their assigned "port of entry". For nearly one hundred and fifty years, until the last such mission in 1547, Chinese "gifts", such as silk thread, brocades, medicines, books, and ceramics, were provided in return for Japanese "tribute", such as lacquerware, bronze vessels, swords, armour, fans, screens, and sulphur (used in papermaking). Chinese copper coinage was also imported into Japan in vast quantities. A 1999 study of 275 Japanese hoards, totaling 3,530,000 coins, found that the Chinese copper coins used in Japan in the Middle Ages were brought over in the