The island is best known for the town of Mitarai (御手洗), an important port of call for ships during the Edo era.

[2] With the development of the Western Circuit (西廻り航路, nishimawari kōro) shipping route through the Seto Inland Sea in the Edo period, the town of Mitarai grew as a port for ships waiting for rising tide or favourable winds.

The port area retains its historical character with groynes, stepped piers and a lighthouse, and is gazetted as an Important Preservation District for Groups of Traditional Buildings.

[5]Most of Ōsakishimojima was formerly administered by the town of Yutaka, with a small portion on the west coast in Toyohama.

[6] Ōsakishimojima is linked by the Akinada Tobishima Kaido road westwards to Toyoshima Island [ja] and onward via a series of bridges to the mainland of Honshu near the city of Kure, Hiroshima, as well as eastwards to Okamura Island, the current terminus of the Kaido.