In the early modern period, Joseon’s diplomatic relations were usually concluded in Beijing in the north, and in Kyoto or Edo(Tokyo) in the southeast. However, when diplomatic, political, or military disputes arose between the two countries, the primary negotiation points were Liaoyang(遼陽) in the Ming dynasty and Shenyang(瀋陽) in the Qing dynasty. If these two regions were the primary points of connection with China, in the case of Japan, it can be said that Tsushima Island(對馬島) served that role.
Tsushima was Joseon’s door and served as a gateway for the envoys of powerful feudal lords(大名) coming from the Japanese mainland and many islands in the Kyushu region(九州). Joseon considered Tsushima as a strategic point and had the Tsushima islanders and others control the Japanese pirates and adulterers. In other words, they were entrusted with the role of a fence and a pillar on the southern frontier of Joseon. When ships carrying envoys such as generals of the Japanese shogunate or powerful feudal lords in Western Japan entered Joseon, they could only do so after obtaining a bunin(文引), which was a permit for passage from the island’s owner. This measure gave the Lord of Tsushima a monopoly on trade rights with Joseon.
If they were to invade, a situation would arise in which numerous seaside villages in Joseon would be damaged, so they proposed a plan to give preferential treatment to the So Clan of Tsushima.
Thus, Joseon chose the policy to stabilize the southern part of the country by giving them a generous reception because Tsushima was a den of Japanese pirates and had the character of a gateway for many Japanese to enter and leave the country.
Since Joseon had practical problems in the trade with Tsushima such as the invasion of Japanese pirates, the agreement of Letter of permission to pass and contract for ships dispatched every year, restriction of control of residents in three port cities(三浦), and the right of fishing license near Joseon, etc., it presented with a gift of tiger and leopard skins not only to the Lord of Tsushima but also to the chief of pirates, the deputy of the Lord of the island, and the various forces of each county. In particular, Joseon favored the Nii Nakamura clan(仁位中村家), the center of the various forces.
In this way, Joseon accurately understood the power dynamics between the Lord of Tsushima and the Nii Nakamura clan, bestowing special and valuable gifts, such as tiger and leopard skins, to each at different levels. Simultaneously, they implemented a policy to ensure effective communication with Tsushima Island by regulating the number of ships dispatched annually.