This longitudinal case study describes a male Korean English teacher's identity development during two years of compulsory military service. An "investment and imagined communities" framework undergirded the thematic analysis of emails, mobile messaging, and casual conversations. Three recursive themes emerged: English user, researcher, and "hyeong" (older brother) identities. The findings indicated the following: Jung's English user identity was manifested in the role of someone who was occasionally asked to perform the task of translating for the U.S. and Korean Armies. His researcher identity reflected his eagerness for further study and interest in academic issues, which was sustained through his interactions with colleagues in the academic community and military comrades. His "hyeong" identity, the counselor, emerged in response to military colleagues' requests for advice on English learning and the importance of English in Korean society. This study shows the need for increased attention to this under-researched population.