According to sociological rational choice theory, students' class-specific educational decisions at key transition points significantly contribute to educational and social inequalities. Yet, while theory missed to clearly accentuate all relevant actors' influences on students' decisions, research generally failed to adequately empirically account for students' individual share in such decisions, but attributed their choices to family background and academic achievement. Drawing on the Japanese case, a refined rational choice model reflecting multiple (f)actors' influence on students' decision-making is introduced, before new evidence on students' actual share in high school choice since the 1990s is presented. Comparative multinomial regressions show the following main findings: (1) Students with concrete educational plans decisively impact their high school choice even when controlling for family background and academic achievement. Students thus clearly impact their own educational pathways and whether inequalitites are reproduced. (2) In spite of the recent policy shift towards more individual choice, students' own educational plans have not become considerably more influential for their final high school placement in 2009 compared to 1995, implying similar constraints for individual choice still. Academic achievement remains decisive for school choice in Japan, as juku have taken over former functions of placement counselling.