Yakushima is a small, mountainous island off the southern coast of Kyushu, Japan, famous for its ancient cedar forests and UNESCO World Heritage status, and a rental car is the most practical way to reach the island's trailheads and coastal villages once you have arrived. Yakushima Airport (KUM) is a compact regional field on the island's northeast coast, with a handful of rental desks operating out of a small terminal building, and pickup is usually quick given the modest number of daily flights connecting to Kagoshima and other regional airports.
From the airport, the island's main coastal road circles most of Yakushima's perimeter, linking the small port town of Miyanoura, where ferries from Kagoshima also arrive, with villages further south and west. Reaching the trailheads for Yakusugi Land or the famous Jomon Sugi cedar, said to be among the oldest trees in Japan, typically means driving thirty minutes to an hour up narrow mountain roads that climb quickly from the coast into cloud forest, so a compact car suited to tight switchbacks is worth requesting over anything larger.
Japan drives on the left, which is worth practicing mentally before setting off if you are used to right-hand traffic, and visitors from most countries need an International Driving Permit issued under the 1949 Geneva Convention alongside their home license to drive legally, since Japan does not recognize the more common 1968 convention permit that many other countries issue. Roads on Yakushima narrow considerably away from the coastal ring road, with single-lane mountain stretches, occasional rockfall and heavy seasonal rain that can affect the interior routes, so checking conditions before a mountain drive and allowing generous time for the return trip make for a smoother visit to this densely forested island, where the pace of travel is naturally slower than on the mainland.