Japan is the world’s fourth-largest economy and a close ally of the United States. Yet its politics are highly anomalous: It is a democracy in which one party, Japan’s Liberal Democratic Party (LDP), wins nearly every election. Even an electoral reform, expected to bring about alternations in power between two large parties, has. The chapter uses data on the outcomes of every Lower House election held since the LDP’s inception in 1955 and public opinion surveys to flesh out the puzzle of LDP dominance. It surveys three explanations for this. One emphasizes structural features of the electoral systems Japan has used and explains how they have translated into advantages for the LDP. The other two probe the reasons why voters vote for the LDP. One holds that voters vote for the LDP because they prefer its policy positions, ideological orientation, leaders, or reputation for competence. The other holds that voters vote for the LDP because of the access to central government resources its politicians enjoy. This chapter explains how over time, real-world events and empirical studies have chipped away at the explanatory power of each account. This warrants another look at this question.