Research on the representation of culture in language textbooks rarely incorporates the concept of global citizenship, despite its increasing relevance to language education in our globalising world. To address this critique, a mixed-method study was conducted to investigate cultural representation in Japanese elementary school English textbooks, and the degree to which students feel connected to the concept of global citizenship. Content analysis of Japanese textbooks and thematic analysis of student and teacher interviews found that the texts are culturally simplistic and did not help this population of students fully realise the values of global citizenship. Meaningful cultural representation may reinforce cultural awareness, open-mindedness, and social responsibility -- the core dimensions of global citizenship. To this end, future English curricula would benefit from supplementary authentic materials, cultural exchange experiences, and explicit discussions of culture between teachers and students.