The rapid development of international education has occurred alongside a growing demand for higher education institutions to educate globally competent graduates. Yet, mobility remains a distant opportunity for most students, and Japanese undergraduate students often cite financial, safety, and job-hunting concerns as obstacles to studying abroad. Internationalisation-at-home has emerged as a viable alternative to mobility in Japan through government-funded internationalisation programs. This article will discuss the impact of cocurricular and extracurricular programs on the development of intercultural competence among 164 first-year Japanese students at two Top Global universities in Japan. Results from a one-year longitudinal, mixed methods study reveal that while formal programs positively affect intercultural competence development, informal intercultural contact on campus negatively affects students' intercultural attitudes. Findings also indicate that student perceptions of intercultural competence at the pre-intervention stage affect engagement with intercultural opportunities on campus, suggesting the importance of introducing interventions prior to higher education.