This study examines the effects of school choice on students and public education using the case of the application-based random assignment system prevailing in Seoul, South Korea. I find little evidence that winning this educational lottery improves students' academic performance, class attitude, or overall manners, which are quality-related indices of public education. While students' school satisfaction increases significantly when they are assigned to their preferred school, this positive effect does not persist over time. I also find no robust evidence that the quality of public education, as measured by examining the behaviours of principals and teachers, is enhanced by South Korea's school choice policy. These results do not align with advocates' arguments that the school choice programme can normalise public education by stimulating competition among schools. One possible interpretation is that students may exploit the school choice program to facilitate their access to private tutoring and that this circumstance does not ultimately raise the quality of public education. Overall, my results suggest that the positive effect of school choice is limited and that a school choice system should be designed carefully.