Yakushima, Island In Japan is the important island. Yakushima is an island of about 500km square and roughly 15 000 islanders to the south of Kyushu in Kagoshima Prefecture, Japan. The highest point on the island is Miyanoura-dake at 1,935 meters (6,360 feet). It is covered in dense forest noted especially for old growth Cryptomeria trees known as Sugi in Japan and magnificent Rhododendrons.