This chapter analyzes teacher induction in Japan through comparative ethnographic narrative (CEN), a blend of reflexive ethnography and narrative inquiry (Howe, 2022). Teacher induction in Japan exemplifies a gradual acculturation into the teaching profession with significant in-service professional development and informal guidance from veteran teachers. Novice teachers spend their first year in an intensive induction program and are required to follow up every 5 years for additional professional development. Japan’s teachers acknowledge the importance of mentoring, the notion of teacher as researcher and the implications of life-long learning. Teacher relationships between sempai/kohai (senior/junior) are critically important to Japan’s teacher induction. In this chapter, the lived experiences of novice, mid-career, and veteran teachers’ collegial relationships and their zatsudan (informal mentoring) are described in detail. Japan’s exemplary teacher induction offers a mirror for us to reflect on our own practices.