Gomu

Gomu was an island district of Ōsumi associated with Yakushima, south of Kyushu. Its wooded mountains and coastal settlements belonged to the Shimazu domain's maritime world. Forest resources became a particular concern of territorial government. In 1595 the Shimazu issued regulations known as Yakushima-okime, restricting the use of the island's cedar. Large-scale exploitation of Yakushima cedar began in 1642, making timber an important part of the island's early modern history.

Island administration changed with that developing relationship. In 1695 the Yakushima deputy's office was replaced by a magistrate's office. Maritime supervision also mattered. In 1708 the Italian priest Giovanni Battista Sidotti secretly landed on Yakushima. Island officials detained him at Miyanoura and reported the incident to the domain authorities; he was subsequently sent to Nagasaki. The episode brought this forested island into the enforcement of Tokugawa restrictions on Christianity and foreign entry. Timber regulation, local officials and watched landing places connected Gomu's settlements to the government of southern Japan.