Juxtaposed with the emerging body of literature about datafication in schooling, this paper examines the increasing encroachment of data into the Japanese education system, in particular, the use of data associated with standardised academic assessments for governance purposes. In so doing, we use the Japanese 'case' to expose the possible limits of the existing English-language scholarship on this phenomenon. By providing a contextualised, descriptive account of how data is incorporated into the three layers of Japanese education bureaucracy (municipal, prefectural, national), we call into question the assumed universality of datafication in schooling and its effect as proffered by Anglo-American education policy scholars. Using the Japanese case, the study elucidates the ways in which the particular policy context of the Anglo-American countries, where datafication has been extensively studied, sets certain limits on the existing discussion and leaves underexplored certain questions that might be more relevant to countries and regions beyond Anglo-American education policy contexts.