In 2008, a new language education policy called "Gaikokugo Katsudou" [Foreign Language Activities] was issued by the Ministry of Education, Culture, Sport, Science, and Technology (MEXT) in Japan. Effective 2011, foreign language education became mandatory in all Japanese public elementary schools for the first time. With this dramatic shift in policy, all fifth and sixth graders in public elementary schools must be provided with 35-credit-hours of English activity class per year. This qualitative study documents language policy processes at two elementary schools in Japan--Seto Elementary School, a neighborhood school in a local city area with three Japanese homeroom teachers and Satsuki Laboratory School, an elite, laboratory school in a metro area with a novice, Japanese teacher of English. Drawing on the ethnography of language policy that acknowledges the critical roles that local practitioners play at "the epicenter of the dynamic process of language policy making" (Garcia & Menken, 2010, p. 262), this study examines the core of the policy process, pointing to multiple, local, dynamic, "de facto" policies that teachers create in their classrooms. In particular, I examine how local teacher identities and their practices interact in class to form their "de facto" policies. I analyze how the macro-level, socially constructed, imposed, and idealized category of teacher identity in Foreign Language Activities is locally negotiated and reconstructed in teachers' day-to-day discursive practices. My ethnographic and micro-discourse analysis suggests that at Seto Elementary School, the textbook served as a de facto policy that shaped the school's curriculum, lessons, and instruction. The teachers' limited conditions including having absolutely no time to plan lessons with their English-speaking teacher and their low English proficiency were critical factors in their views and practices that did not allow them to explore, access, and make use of their expertise. Although my micro-discourse analysis identified evidence of negotiation in their interpretations and practices of the policy, overall, their exercise of agency remained limited within the top-down policy context. In contrast, at Satsuki Laboratory School, the top-down policy was not dominant but selectively and partially implemented in a teacher's classes. She was given time, space, and language competency to fully exercise her agency in negotiating and recreating the policy while exploring and developing her professional identity and expertise as an English teacher. By providing empirical insight into the dynamic nature of identity construction in interaction, this project reconceptualizes and reconsiders mechanisms of language policy by highlighting the linguistic, cultural, and professional dimensions of local teacher identities in the language policy process. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]