This book examines the process of identity (re)construction for assistant language teachers (ALTs) in foreign language classrooms in Japan, using Narrative Inquiry as a tool to provide a multifaceted perspective on their personal and professional growth. To develop a thorough understanding of the classroom, the author proposes three different types of awareness from the perspective of sociocultural theory. Each type of awareness is a unique lens through which to see the teachers’ world of language teaching within the classroom. Finally, the book discusses teacher development, teaching theory, and identity based on analysis of the narrative data.  The book offers useful pedagogical insights that may have implications for teacher development and principles of language team teaching for teachers, teacher trainers, ALTs, boards of education, and university students of English and language education, including English as a Foreign Language (EFL).