Former Prime Minister Koizumi's surprising victory within the Liberal Democratic Party in 2001 and his subsequent popularity as prime minister led to increased interest in the study of populism in Japan. In addition to Ōtake Hideo's prominent contributions, several others have also employed populism as a prism to study Japanese politics. Compared to the major debates on populism and particularly on the populist radical right in Western Europe over the last two decades, however, the study of Japanese populism seems to (...) be at a less mature stage. Lessons may be learned from the European literature for the community studying Japanese populism. This paper first summarizes the studies on Japanese populism. Then, the main discussions and arguments presented in the academic literature on the PRR in Europe are discussed. Next, this study evaluates how arguments found in studies of European populism can be exploited in further research on populist politicians and parties in Japan. The author recommends further studies on conceptual definitions, on the classifications of politicians and parties, and on explaining the emergence and persistence of these parties and politicians. The findings in this paper encourage and support further research on populism in the Japanese political system. (shrink)