The aims of the present study are two-fold. The first aim is to reveal the cultural and linguistic issues that need to be considered in the development of curricular content and sequencing for teaching mathematical proof in secondary schools in Japan. The second aim is to elaborate an epistemological perspective that may allow us to understand what constitutes proof in the curriculum of a given country, so that our results may be applied in international contexts. By doing so, we then elaborate a reference epistemological model which may allow us to understand what constitutes mathematical proof in different countries.