In accordance with the multilingual turn in SLA (May, S. 2014. Introducing the 'multilingual turn'. In "The Multilingual Turn: Implications for SLA, TESOL and Bilingual Education," ed. S. May, 1-6. New York, NY: Routledge), researchers are now directing more attention to the motivational dynamics associated with learning multiple languages, including the interrelationships between motivation and learners' sense of self. In contrast to research focused on language learners' psychological relationship to languages from the perspective of self-systems, this research instead takes a more identity-focused perspective that looks at motivation in light of learners' orientations towards ideological discourses associated with languages. It draws on longitudinal qualitative interviews and supplementary data from five Chinese university students in Shanghai who are majoring in Japanese while continuing to study English. The analysis highlights that the learners experienced a number of important identity-tensions as they attempted to reconcile ideological discourses on language with their own multi-layered identity positions and perspectives towards language learning. The discussion details the ways that learners mobilise their interpretive resources to evaluate instrumental and humanistic orientations towards language within macro-, meso- and micro- contexts and make agentive decisions that shape their motivational trajectories and multilingual identities.