Shudan-shushoku, the administrative young workers' labor migration program, was carried out under the control of the Japanese Ministry of Labor in the high-growth period of Japan (1955-1973). This system was also applied to Okinawa (Ryukyu), although Okinawa was ruled by the United States Civil Administration of the Ryukyu Islands (USCAR) until 1972. The Government of Japan had residual sovereignty over Okinawa and was able to include it in the Japanese labor market. When and how was this program of migration from Okinawa to mainland Japan started? Why did the Government of the Ryukyu Islands have to start and maintain such a migration system? And what did young workers from Okinawa think of the geographical/social distance between the homeland and mainland Japan?The purpose of this paper is to clarify some aspects of this migration program. The paper focuses especially on the acts of the three Governments: the USCAR, Ryukyu and Japan, and on the thoughts of young workers themselves. The results of this study are summarized as follows.In the 1950s, because USCAR had to employ a large labor force for American military bases in Okinawa with small salaries, the growth of industry in Okinawa was restrained by economic policies. Since the labor market in Okinawa had few employment opportunities, the Government of the Ryukyu Islands negotiated with the Government of Japan on this problem, and finally USCAR also allowed migration to mainland Japan. As a result, Shudan-shushoku was initiated in December 1957. Because the labor force had been undermanned in the high-growth period of mainland Japan, job offers to young in Okinawa were increasing year by year.As the numbers of labor migrants to mainland Japan increased, some social problems (e.g. suicides, neuroses, or crimes) caused by young workers frequently occurred. Because there was a geographical/social distance between the homeland and the mainland, some young workers did not assimilate into the culture of the mainland and were often discriminated on the mainland. Therefore, the Government of the Ryukyu Islands held training sessions for young migrants to assist in dealing with these issues from 1961. However, in 1963, the High Commissioner of USCAR, Paul Caraway, ordered the suspension of shudan-shushoku. The USCAR explained that the reason for this suspension was that 'our people are discriminated in mainland Japan.' The Governments of Japan and the Ryukyu Islands criticized USCAR and it revoked this suspension but claimed that the system of labor migration must be improved. As a result, the Regulation of labor migration to a foreign country was enacted by the Government of the Ryukyu Islands in 1964.Migrants themselves had an intention that differed from that of both governments. Many of the migrants decided to migrate to mainland Japan because it was not only difficult to get a job in Okinawa, but also because they were attracted to city life in mainland Japan. It was said that some migrants even used this labor migration program for the purpose of travelling to the mainland. However, the real mainland was not the same one that they thought it would be before migration. Some of them did encounter discrimination in their workplaces.