There has been a drastic decrease in the number of young Japanese voters. What are the reasons why new generations are less engaged in elections compared to the old ones? It is the claim of this paper that the declining turnout is due to a generational realignment in combination with institutional obstacles. The incentives to vote are decreased by the electoral rules, campaigning practices, and geographic mobility. I situate the question in a comparative politics approach that connects the aspects of political socialization, outreach of political parties and institutional design. According to the theory, three processes are predictable, including differentiated political priorities, transactional disengagement due to economic precarity, and procedural friction, which increases the cost of voting by mobile populations. The project employs mixed methods design methodologically. It examines the turnout patterns in national and subnational elections based on electoral results and age-cohort data, first. Second, it is based on national survey items concerning trust and issue salience. Third, it will provide some comparative case studies of two prefectures and two municipalities where youth turnout has been divergent. The causal tracing is enhanced by semi-structured interviews with the party organizers and youth activists. There is an initial indication that young voter turnout cannot be traced down to apathy. Structural factors matter. The lived issues of young cohorts are seldom discussed by parties. Disengagement is aggravated by administrative barriers and poor local connections. Results are used in policy formulation on both turnout and institutional reform.