Tonoshō is a town and port in Shōzu District, Kagawa, Japan, with a population of 12,915. The town lies on the west coast of the island of Shōdoshima—the second-largest island in the Seto Inland Sea—and it is the main passenger access for the island. First settled around the 8th century, the town center grew into a complex maze of streets during the war-torn Muromachi period (1336–1573) to inhibit enemy forces. The town was officially incorporated in 1898, and today sesame oil, olives, sōmen noodles, fishing and tourism are important industries.

Kagawa Prefecture is a prefecture of Japan located on the island of Shikoku. Kagawa Prefecture has a population of 949,358 and is the smallest prefecture by geographic area at 1,877 square kilometres (725 sq mi). Kagawa Prefecture borders Ehime Prefecture to the southwest and Tokushima Prefecture to the south.