Given its intertwined nature with culture, language is an undoubtedly significant vehicle that helps learners understand their interlocutors in intercultural communication. However, culture in EFL education is often used to distinguish and classify people regarding nationality, race/ethnicity, class, gender, history, and cultural activities and practices rooted in geographical categorization (Irani & Dourish, 2009; Kramsch, 2014). Within the framework of critical intercultural education (Dervin, 2020), this study investigates cultural and linguistic values and beliefs embedded in supplemental learning materials for Korean Grade 6 EFL students. Using mediated discourse analysis (Wells & Wong, 2012), this study analyzes hidden messages and meanings in multimodal semiotic systems within the material (i.e., an animated video clip). Findings reveal ideological values of English and Korean and the deficit view of non-Korean ethnic people. This study urges teachers, researchers, textbook makers, and other stakeholders to challenge the practice of the us-and-them dichotomy in Korean EFL education and develop interculturality among students and teachers.