As non-Catholic teachers are being hired into Catholic high schools, they are inducted into the school mission that participates in the Catholic Church’s mission for evangelization. The research on the non-Catholic teachers’ perspectives and experiences of this mission formation is underdeveloped. This study explores the process of Catholic school mission formation conducted by school leaders for non-Catholic teachers in the region of Southern California. Specifically, it examined the perception of non-Catholic teachers’ experience about their mission formation at the Catholic high schools. Simultaneously, it investigated the perception of school leaders in their practice of mission formation for non-Catholic teachers. Drawing upon the phenomenological school of thought, this study uses the method of narrative inquiry. Through semi-structured interviews of non-Catholic teachers and school leaders, this study collected data through their stories of mission formation in the Catholic high school system. The participants for this study were selected through purposeful and convenience sampling. According to the findings, the study demonstrates a relationship of the participants’ conceptual framework of evangelization and their self-understanding of participating in mission, as well as to how effective the school leadership supports them in school mission. Corresponding to Shields’ (2008) study, the study concludes that any induction program will have to admit the limits it can offer but consider the critical starting point: the story that brought them to the school. The findings also demonstrate an opportunity for school leaders to reconsider their practice.