Flag of Okinawa Prefecture

The flag's charge is the official emblem of Okinawa Prefecture.^[1] It consists of three circles stacked on top of each other, alternating between red and white. The inner two circles are positioned upwards. The outermost circle is red and represents the Pacific Ocean, which surrounds Okinawa Prefecture. The middle circle is white and represents the letter "O" in the rōmaji spelling of "Okinawa". It is also meant to symbolize a circle of people united together. The innermost circle is red and represents the prefecture's potential for development. Accordingly, the Okinawa Prefectural Government describes the emblem itself as "a symbol of the [Pacific] ocean, peace, and development."^[1]

The Empire of Japan transformed its vassal the Ryukyu Kingdom into the Ryukyu Domain in 1872 and annexed it outright in 1879, establishing Okinawa Prefecture.^[2][3] The de jure independent kingdom did not have a national flag.^[4]

During the U.S. military occupation and later civil administration of the Ryukyu Islands from 1945 to 1972, the U.S. flag was the only national flag permitted to fly on the islands.^[5] However, this did not apply to merchant ships from the islands, which could not fly either the U.S. flag nor the Japanese flag (日の丸, Hinomaru) as their civil ensign due to the U.S. civil administration's ambiguous status under international law. The U.S. civil administration thus proclaimed on February 27, 1952, the adoption of a "Ryukyuan ship flag" – a signal flag letter D (Delta) with a triangle at the fly cut off. This caused routine confusion among other vessels, culminating in the Kyuyo Maru incident of 1962, in which a Ryukyuan fishing boat that had entered Indonesian territorial waters was shot at by an Indonesian naval aircraft that could not deduce the boat's nationality. Four Ryukyuan fishermen were killed or wounded, resulting in uproar on the islands and demands for the Hinomaru to be adopted as the Ryukyuan civil ensign. The issue ultimately made it to the Japan–U.S. Consultative Committee of 1967, in which the two countries agreed that Ryukyuan ships would henceforth fly the Hinomaru alongside a triangular flag with the name "Ryukyus" written in Japanese kanji (琉球) and all caps in English (RYUKYUS).^[6]

After diplomatic meetings in 1969, the U.S. agreed to return Okinawa Prefecture to Japan within three years.^[7] Following the signing of the 1971 Okinawa Reversion Agreement, the Japanese government held a public, nationwide competition to design an emblem for the prefecture. A total of 186 designs were submitted.^[8] On April 24, 1972, the Prefectural Emblem Selection Committee chose a design submitted by a man from Kyoto Prefecture and decided that the colour scheme would be blue, white, and red from the outermost to innermost circle.^[8] However, the committee soon discovered that the chosen design and colours resembled the mark of the All Japan Kendo Federation, and so the innermost circle was changed from red to blue on May 9.^[8] The emblem became official six days later on May 15, when the Ryukyu Islands were returned to Japan.^[9] On October 13, the prefectural government announced the adoption of the prefectural flag and the changing of the prefectural emblem's blue circles to red.^[10]

• Flag of Ryukyu