Japanese Lesson Study (JLS) is a professional development method, involving teachers collaboratively planning lessons, observing their enactment, then discussing observations of teaching and learning. This paper explores translation of JLS internationally, seeking to understand how and why it is adapted and how an understanding of national culture and implementation paradigms might support translation. We begin by examining evidence on adaptation and challenges of JLS implementation internationally, finding both deviation from the seven components of JLS, and qualitative evidence of perceived challenges to successful implementation. Further we explore two bodies of the literature explaining how and why such adaptations occur. First, implementation science reveals that full fidelity appears not to be amenable to the complexity of education innovations like LS, but that adaptation is fraught with challenges, with no linear pathway. Secondly, Hofstede's and colleagues' dimensions of culture enable us to hypothesise about how Japan's culture might have framed development of JLS, and to predict possible challenges when translated into a host nation. Finally, we hypothesize as to the relationship between adoption of either fidelity or adaptation implementation paradigms, and identified differences between Japan and the host nation's national culture, suggesting avenues for further research which may serve to test hypotheses empirically.