Complex sentence: However, the Tokugawa shogunate started trading again with the Korea by concluding the with the So clan of Tsushima Island in 1609 and established a relationship of almost equality through mutual visits of Korean messengers.
Split into simpler sentences: However, the Tokugawa shogunate started trading again with the Korea by concluding the. The retainer of the Tokugawa shogunate, and the family (local lord) of Tsushima Island in 1609 and established a relationship of almost equality through mutual visits of Korean messengers.