This article analyzes the historical transformation of math education in South Korea before and after 1945. Two prominent Korean mathematicians of post-1945 South Korea, Yoon Sik Choi and Rimhak Ree, are the cases in point. The two mathematicians received their higher education in mathematics and physics at prewar Japanese universities, Tokyo Imperial University and Keijo Imperial University, respectively. Their colonial background did not block them from achieving a hegemonic position in math education and research in post-liberation South Korea. Choi graduated from Tokyo Imperial University, where Takagi Teiji taught. Takagi studied at the University of Göttingen with David Hilbert and Felix Klein. The Göttingen group emphasized the synthesis of algebra and geometry and initiated the so-called “Klein Reform.” The Klein Reform entered colonial Korea through the Japanese Empire during World War II. The Japanese mathematicians positioned functions at the center of math education. It is striking that the two former colonial elites, Choi and Ree, successfully claimed their intellectual leadership among South Koreans by resuming the Japanese wartime curriculum reform in the name of universal mathematics. So, postcolonial math education in South Korea was redefined by former colonial elites who selectively borrowed from the colonial system.