Research and development on fast breeder reactors (FBRs) started in Japan in the mid-1960s, leading to the experimental FBR JOYO which went critical in 1977. It was followed by the prototype FBR MONJU which started operating in 1994. A 600 MWe loop-type demonstration liquid-metal-cooled FBR (LMFBR) is now under study, especially emphasizing its safety and economy. A demonstration plant could be in operation several years after 2010. Japan expects a significant fraction of world nuclear energy mix to be provided by FBRs by the end of the 21st century. This paper has detailed descriptions of the activities of the various Japanese organizations involved in FBR development, as well as program funding and policy considerations.