Ishigaki Island, which has been attracting attention as a tourist destination in the world in recent years, is geographically closer to Taiwan than the main island of Okinawa, and belongs to a subtropical region in terms of climate. The Tropical Agriculture Research Front (TARF), a research base of JIRCAS on Ishigaki Island, is the only Japanese agricultural research institute capable of conducting empirical research in the cultivation environment of tropical crops, and has a major mission to contribute to domestic and overseas agriculture. TARF is conducting research on mangoes and passion fruits with the aim of contributing to the promotion of tropical fruit tree production in both developing countries and Japan. Since these fruits are rich in nutrients such as vitamins and have high commercial value, research that leads to the development of excellent varieties is expected to benefit both domestic and overseas consumers and producers.