AbstractImagined identity, which opens up a variety of future possibilities for language learners, has been theorized from seemingly incompatible psychological and sociological perspectives in applied linguistics. Researchers have thus appealed for a transdisciplinary theoretical combination of these perspectives for a more nuanced understanding of language learning in context. This article makes the case for a synergistic theoretical framework of investment and motivation to theorize the idiosyncratic relationship between individuals’ imagined identity and language learning behavior. Empirical findings from a multiple‐case study conducted in Yunnan, in the south‐western corner of China, are presented to demonstrate how this framework enables a nuanced analysis of individuals’ language learning. Findings suggest that the interconnectedness of imagined identity, motivation, and investment is informed by both learner agency and contexts. This paper proposes that learners’ development of imagined identities and ways of investing in learning could be individually different, even under similar circumstances, which indicates the need for personalized teaching to improve learning outcomes. This synergistic framework thus provides implications for pedagogical practices and a need for personalized teaching.