The vast number of islands that were invaded/recaptured by the Allied forces were not highly occupied by civilian populations. Iwo Jima had virtually no inhabitants. Very different experiences were encountered on Saipan, in the Philippines, and on especially on Okinawa whose pre-invasion civilian population was estimated at 300,000 people. Okinawans were Japanese citizens, at least in law.

After the 1879 annexation of the Ryukyu Kingdom, Okinawa was made a prefecture of Japan. By the time of the Allied landings, Okinawans were Japanese citizens in law: subject to conscription, taxation, and wartime mobilization like all other Japanese. Their cultural and social status was something different. The longer and deeper roots of Okinawa were Chinese in custom and perspective and as a result, Okinawans were often regarded by mainland Japanese as a peripheral or inferior people, with distinct language, customs, and history. The Okinawan (Ryukyuan) language was suppressed in schools in favor of standard Japanese. Children caught speaking Okinawan dialects were sometimes punished. Mainland Japanese officials and soldiers stationed in Okinawa frequently treated locals as less disciplined, less loyal, or “not quite Japanese.” 

Prior to 1944, Okinawans could join the Japanese military but were rarely assigned to combat ranks, most often serving in labor units, auxiliary roles, or support services. After the fall of Saipan in July 1944, Japan recognized that Okinawa was likely to be the next U.S. target. At that point the 32nd Japanese Army was stationed on Okinawa, and the Japanese authorities began mass mobilization of the Okinawan population. The mobilization had three primary elements: