The beginning of rice agriculture in Japan impacted every aspect of life in most parts of the archipelago. It was the Japanese version of the ''Neolithic Revolution.ÕÕ Because rice is so important today for Japanese and thought to have been so since the Yayoi period, when and how rice agriculture began in Japan has been intensively studied. Accordingly, three hypotheses, (1) Northern, (2) Chanjian (central coastal China), and (3) Southern routes have been proposed. The third hypothesis was originally proposed by the well-known ethnologist Kunio Yanagita in 1952. Since then, many scholars have attempted to examine this hypothesis. The possibility of this hypothesis based on archaeological, botanical, and ethnological data that have been accumulated in the last fifty years is summarized. Direct data, plant remains that I was able to collect and analyze to test this hypothesis are evaluated. The archaeobotanical data suggest that food production began on the island of Okinawa from the eighth to tenth centuries a.d. and foragers were living on the island during the Yayoi period. The data thus agree with archaeological data and the Southern route hypothesis is rejected.