Although politics and religion were once tightly fused in Japan, today religion plays a weak role in politics and society. The mosaic of religions and sects that exist in Japanese society – including Buddhism, Christianity, Confucianism, Shinto, Taoism, and the many “new religions” that mix aspects of Buddhism and Shinto – does not create or reinforce political cleavages. Although once religion played an important role in politics in society, in the postwar period religion has become far less relevant to politics.

In the nineteenth century and prewar and wartime periods of the twentieth century, religious ideology was central to the political notions of the Japanese state and nation. Religious worship of the emperor, militarism, imperialism, and nationalism were tightly intertwined. After Japan's surrender in World War II, these doctrines were suppressed. Subsequently, religion in contemporary postwar Japanese society is viewed by most observers as politically irrelevant, or at most on the political periphery.

In this chapter, we explain this dramatic shift by focusing on the fluid nature of religious theology, and how political elites have historically sought to integrate new doctrines, and to reinterpret traditional religion in order to use religion as part of the solution to pressing political problems. We begin with an overview of Japan's two main religions, Shinto and Buddhism, their origins, and the ideological as well as geopolitical conditions that helped to foster syncretism between them.