The notion of English as a multilingua franca (EMF) positions English within multilingualism, and EMF awareness prepares students to communicate effectively in this multilingual world of mobility. The present paper explores how, if ever, EMF-aware pedagogic intervention influences Japanese students' perceptions of their communicative practices, particularly for English-major undergraduates in L1-shared classrooms. This intervention was made by providing opportunities for participants to engage in EMF and by examining their first-hand experiences and published EMF communication extracts in the classrooms. Empirical data from an open-ended questionnaire demonstrate that multilingual and transmodal accommodation was a way for them to notice and take advantage of global networks, develop capability and confidence in communication, and foster sensitivity to interactants' backgrounds. The data also illustrate the invaluable role of individual multilingual experiences as classroom 'materials', and suggest that discussing these experiences potentially turns L1-shared classrooms into EMF scenarios through foregrounding students' multilingual repertoires.?