This study explores graduate students in a master course as well as teacher educator’ learning from each other and how their perspectives changed as they reflected on their shared perspectives of lesson observation through their participation in a physical education lesson study (PELS). The graduate students retained three different perspectives: "viewpoint change type," "viewpoint change type," and "viewpoint increase type. This was influenced by their own expertise and identity, based on their educational experiences. In addition, the influence of the teacher educators was also significant. Furthermore, through the process of PELS and the subsequent dialogue, professional socialization of the graduate students was facilitated by them "learning together." However, it was suggested that their own professional identity may inhibit their learning.