Naha is the capital city of Okinawa Prefecture, the southernmost prefecture of Japan. As of 1 June 2019, the city has an estimated po…Naha is the capital city of Okinawa Prefecture, the southernmost prefecture of Japan. As of 1 June 2019, the city has an estimated population of 317,405 and a population density of 7,939 people per km². The total area is 39.98 km².