Shimoagata

Shimoagata belongs to the southern part of Tsushima, the mountainous island between the Japanese archipelago and the Korean peninsula. Limited farmland encouraged reliance on fishing, woodland resources, and exchange with other shores. Harbours and coastal routes connected settlements separated by rugged terrain, while the island's position gave local seafaring knowledge a significance extending beyond subsistence. Movement across the strait could bring both commercial opportunity and political danger.

The Sō family governed Tsushima and became an important intermediary in relations between Japan and Korea. Its castle town was Tsushima Fuchū, present-day Izuhara, in the south of the island. After the Japanese invasions of Korea disrupted relations in the 1590s, the Sō worked to restore them: a Korean mission came to Japan in 1607, and trade resumed in 1609. The island's ports and interpreters remained important to communication across the strait.