Using second language (L2) socialization theory as a theoretical framework, this book investigates the ways in which four advanced learners of Japanese on an immersion program in the USA exercise their agency to pursue their language learning goals. The work presents their learner portraits and documents the different ways in which the four learners negotiate the meaning of their participations in the new community of practice, navigate and shape the trajectories of their learning and eventually achieve their goals of learning from their emic perspectives. The book re-examines Norton's (2000) constructs of investment, investigates its applicability and argues that L2 learners' desires and drives for learning an L2 are more diverse, unique and contextually situated than Norton's notion of investment alone can explain. The research will be of interest to researchers and students in the fields of applied linguistics, second language acquisition, foreign language education and language and literacy education.