The current study aimed to formulate the function of multiculturalism, tolerance, and social justice in Indonesian society. This study was conducted in three diverse cities of East Java are Surabaya, Bangil, and Kediri. To gather the data, the study opted the quantitative-explanatory perspective from four hundred (400) preliminary respondents. The results were compiled through a structured questionnaire and presented in tables, figures, and percentages. The study explores the multicultural learning systems at school that are useful for promoting harmony among people belonging to various segments, and cultural and religious backgrounds in society. The current findings of this study are useful for the development of curriculum in multicultural setup(s) for creating harmony among the diversity of students in educational institutions. It is also suggested that multicultural discourse is important to promote harmony, social justice, and create an integrated environment in the society.