Two Professional Learning Communities of physics teachers from different high schools voluntarily participated in Lesson Study as a means of professional development. The five teacher-participants and one participant-researcher partook of two Lesson Study cycles, each of which focused on student physics misconceptions. The Lesson Study resulted in two topics of physics: projectiles and gravitation. The researcher aimed to determine what happens to secondary physics teachers who undergo Lesson Study through this phenomenological case study. Specifically, (1) What is the process of Lesson Study with secondary physics teachers? and (2) What are the teacher-reported outcomes of Lesson Study with secondary physics teachers? Overall, Lesson Study provided an avenue for secondary physics teachers to conduct inquiry on their students in an attempt to better understand student thinking and learning. As a result, teachers collaborated to learn how to better meet the needs of their students and self-reported growth in many areas of teaching and teacher knowledge. The study resulted in twelve hypotheses to be tested in later research centering on idealizing the process of Lesson Study and maximizing secondary physics teacher growth.