Okinawa Island is the largest of the Okinawa Islands and the Ryukyu (Nansei) Islands of Japan in the Kyushu region. It is the smallest and least populated of the five main islands of Japan. The island is approximately 106 kilometres (66 mi) long, an average 11 kilometres (7 mi) wide, and has an area of 1,206.98 square kilometers (466.02 sq mi). It is roughly 640 kilometres (400 mi) south of the main island of Kyushu and the rest of Japan. It is 500 km (300 mi) north of Taiwan. The total population of Okinawa Island is 1.4 million.

Puerto Rico, officially the Commonwealth of Puerto Rico and from 1898 to 1932 also called Porto Rico in English, is an unincorporated territory of the United States located in the northeast Caribbean Sea, approximately 1000 miles southeast of Miami, Florida. Puerto Rico is an archipelago among the Greater Antilles located between the Dominican Republic and the U.S. Virgin Islands.