To investigate benefits and challenges to engage teacher candidates in Japanese lesson study, defined as a collaborative, reflective, and iterative teacher development process, we analyzed reflective papers submitted by 60 teacher candidates studying at an Ontario faculty of education, engaged 20 practicum associate teachers in a group discussion, and considered the reflective notes of the course instructor (first author). Findings suggest that Japanese lesson study provides opportunities for teacher candidates to build professional learning communities, to deepen understanding of curriculum and pedagogy, and to develop habits of critical observation, analysis, and reflection. Although benefits of lesson study are numerous and significant, our research identified implementation challenges related to time, practicum placements, and the professional development of associate teachers.