This study explores how South Korean teachers' beliefs about social justice teaching intersect with their intergroup contact experiences when teaching migrant students under expanded curriculum autonomy. A comparative qualitative case study approach was used, drawing on interviews, classroom observations, and stimulated recalls. The findings reveal three models of social justice teaching -- functional, critical, and liberal -- as manifest in each teacher's practice. The discussion highlights two key aspects: First, regarding contact experiences, teachers' experience of being minoritized in intergroup contact has a more pronounced effect on their prejudice reduction than the density or frequency of contact per se; and indirect contact with outgroup members can be as effective as direct contact in reducing stereotypes. Second, concerning teacher beliefs and policy implementation, teachers' beliefs significantly shape their interactions with minoritized students; and increased curriculum autonomy does not necessarily lead to critical social justice teaching. Implications for teacher education are discussed.