Okinawa's Population The population of Okinawa is about 1.3 million, almost 90% of whom live on the main island of Okinawa. The population of Naha, the capital of the prefecture, is about 300,000, while the population of Nago, where the G8 Summit meeting will take place, is about 55,000. It is well known that many people in Okinawa live for a long time. The average life expectancy in the prefecture is 77.22 years for men (the fourth highest in Japan) and 85.08 years for women (the highest in Japan). Particularly striking is the proportion of centenarians (people aged 100 or over). While the average for all of Japan is 4.48 per 100,000 people, in Okinawa the figure soars to 15.8.