Prior studies on children's perceptions about race have heavily focused on children in heterogeneous nations of the Western world. On the other hand, children in mono-ethnic nations remain underrepresented. Thus, this study explored the perceptions of children in one of the world's most homogeneous nations, South Korea. We investigated how children in South Korea perceive themselves and other races, as well as how multicultural education can influence the racial attitudes of children. Using the doll tests and interviews, this study identified three key findings. Firstly, only a few children were able to correctly differentiate all three types of races---Asians, Blacks, and Whites. Secondly, very few children viewed Blacks positively, while a significant number of children favored Whites. Thirdly, while the multicultural lesson was generally quite effective, its impact was notably lower on children who had already developed perceptions about race.