This paper is a report on the foreseen benefits and challenges on mathematics teacher professional development as the teachers in a small private school in Antipolo City, Philippines were sensitized to the notion of Lesson Study. Utilizing the Anthropological Theory on Didactics as an analytical tool, the teacher’s utterances regarding their lived and imagined experiences during a two-week training on Lesson Study were analysed. Three main issues emerged: 1) The importance of having concrete images of non-traditional mathematics teaching; 2) The affordances brought about by having supportive leadership; and 3) Collaboration as an empowering factor for teachers.