This paper examines how social isolation in a non-Anglophone context where English is not the main language of instruction for local students but is for international students, has unintended consequences for social capital formation among the latter. What factors influence international student network formation in such places where linguistic barriers are institutionalised and what are their consequences not only during college but beyond, in shaping students' career plans? Using qualitative interview data with 67 international (originating from Asian countries) and domestic students in Japanese universities, we find that such institutional barriers negatively promote greater isolation of international students but positively encourage the formation of diverse multinational ties -- a process through which international students gain ideas, confidence and direction regarding their post-graduation career plans to work transnationally.