High School Citizenship Education (CEDU), particularly classroom instruction, is widely expected to increase youth electoral participation, as suggested by a substantial body of research in Western contexts. However, most studies focus on the quantity of instruction (e.g., exposure to civic/political knowledge content) rather than its quality (e.g., students’ subjective classroom experiences and emotional responses). Moreover, they typically examine youths who are currently studying CEDU or have recently completed it, leaving the longer-term persistence of CEDU’s effects relatively underexplored. To address these gaps, this study draws on the CEDU and Achievement Emotions literature and conducted a survey with youths (18–29) in Japan (N = 428). It asks to what extent (1) high school CEDU predicts political knowledge and electoral participation in adulthood, and (2) these effects are conditioned by youths’ emotional experiences during civics classes. Findings suggest that neither exposure to civics classes nor experiences of an open classroom are robust predictors of voting in the 2024, 2025, and 2026 national elections. However, greater exposure to civics classes is positively associated with higher levels of political knowledge. Political knowledge, in turn, consistently and strongly predicts voter turnout across all three elections. Yet, the association between formal CEDU and political knowledge varies depending on youths’ subjective classroom experiences - higher boredom and more open classroom climates weaken the positive effect of formal instruction. This study highlights the emotional dimensions of CEDU and youth turnout, and suggests that its association with adulthood voting behaviour could be indirect, operating through political knowledge.
