In Japan, in collaboration with the Ministry of Education, Culture, Sports, Science and Technology (MEXT), the implementation of the IB has been spreading, and the number of PYP, MYP, and DP schools has been increasing every year. The importance of developing International Mindedness in the IB program is stated in the program guides. The purpose of this paper was to (1) summarize the discussion of the framework for capturing the international mindedness of the IB from previous studies and (2) examine how the development of international mindedness is corresponded to the stages of learners’ development. As a result, first, the PYP provides a detailed definition of international mindedness and its connection to the learner profiles and curriculum. Second, the MYP emphasizes aspects of skills such as multiple and diverse perspectives and critical reflection. Third, the analysis revealed that the DP provides a means of embodying an international perspective in the classroom in each subject area.