Sō clan
The "tozama" Sō clan were allowed to continue to rule Tsushima. Tsushima and the area around Tashiro in Hizen Province were included in the clan's fief ("han"), rated as worth 100,000 "koku" for its diplomatic and economic importance, though its agricultural production was actually under 30,000 "koku" per year. After the clan managed to resume diplomatic relations with Korea, the Tokugawa shogunate entrusted it with diplomatic negotiations and trade with Joseon.