Foreign language teaching research in Japan has modeled its research methodologies after the ones of psychological research, and gradually incorporated cognitivism and scientific methods as the most dominant research norm in a few decades. However, after the impact of what is known as the reproducibility crisis in psychology, foreign language teaching researchers have not readily reacted to the issue. The authors speculate that the ignorance was jointly caused by two different types of perspectives on reproducibility as a norm of research practice. One can be described as beliefs such as “the practice of foreign language teaching research in its status quo is in line with the research norm of natural sciences”, which we call the naïve perspective. The counterpart of this is the second one, and it can be best described by the attitude that, from the beginning, abandons the pursuit of reproducibility in foreign language teaching research. The article critically reviews both perspectives, and claims that the naïve perspective is simply inappropriate, but the pursuit of reproducibility in foreign language teaching research can be fairly justified in terms of its functional aspects from pragmatic views. Also, the article discusses multi-dimensionality of research methodologies and political consequences of research methods.