Japan’s southwest arc runs from Kyushu toward Taiwan
The Ryukyu or Nansei Islands form a Japanese chain stretching southwest from Kyushu toward Taiwan, split administratively between Kagoshima Prefecture’s Satsunan group and Okinawa Prefecture farther south. Climate swings from humid subtropical north to tropical rainforest south under heavy rain and typhoons.
The northern Ōsumi and Tokara islands belong culturally to Kyushu, and their people speak the Kagoshima dialect of Japanese. Amami, Okinawa, Miyako and Yaeyama are home to the Ryukyuan peoples, named after the old Ryukyu Kingdom. Apart from the outlying Daitō group, the islands form a single continuous arc.
The United States administered them after the 1951 San Francisco treaty that closed the Pacific War, and the Okinawa reversion agreement of 1971 handed them back to Japan. The Senkaku group at the far south-west is claimed by China and Taiwan.
There are two ways of splitting the chain. Administratively, the Northern Ryukyus are the Kagoshima islands, called Satsunan in Japanese, and the Southern Ryukyus are those in Okinawa Prefecture. Geographically, the Tokara Strait and the Kerama Gap divide three groups: Ōsumi and Tokara in the north, Amami and Okinawa in the centre, and Miyako and Yaeyama in the south. The Japan Coast Guard’s list runs from Tanegashima and Yakushima through the Amami, Okinawa and Kerama groups to the Sakishima, or Further Isles, ending at Ishigaki, Iriomote and Yonaguni. Japan’s mapping authority and the Coast Guard still differ on some names, though on 15 February 2010 they settled on Amami-guntō for the Amami Islands.
Climate grades from humid subtropical in the north to tropical rainforest in the south, noticeably warmer than Kyushu, Shikoku or Honshu. Heavy rain and summer typhoons are common, while winters stay mild and the sea is at its clearest.
Source: Ryukyu Islands
