Ishigaki

Ishigaki needs 3 days: Kabira Bay, with turquoise water and white sand where swimming is banned due to strong currents -only glass-bottom boat tours are allowed-, on one, and snorkeling or diving among the Shiraho coral reefs, among the most extensive in Japan, for the rest. April-June and October-November avoid both summer typhoons and winter cold. It's expensive by Japanese standards, with most of the spend on water activities. It's the gateway to the Yaeyama Islands, Japan's southernmost and least populated archipelago, closer to Taiwan than to Tokyo, with a coral reef ecosystem that survived recent global bleaching events better than almost anywhere else in the country.