:In east-asian countries, there was no "national flag" or the concept until the late 19the centuries. The Hidari-Mitsudomoe (Fijai-Gumun in Okinawan), or the crest of three comma-shaped figures in a circle has been sometimes introduced as the national flag of Ryukyu Kingdom, but the crest originally was a family crest of Sho royal family, and not the national flag. Of cource the flag had been sometimes used as one of ship flages of Ryukyu. But it was no national flag of Ryukyu and nobody call it as the national flag in the world of the Ryukyu(Okinawa) historiography today. 

And the flag Midari-Mitsudomoe with 3 colors was designed for the flag of Ryukyu Seifu (United States Civil Administration of the Ryukyu Islands) in 1950. and it was not adopted. The draft of the flag is preserved at the United States National Archives and Records Administration. Japanese Wikipedia doesn't use the flag. Please refer to the site. Thanks,