Americans stationed in occupied Japan at the close of World War II claimed to be bringing religious freedom to a country where it did not exist. They described Japan’s 1889 constitutional guarantee of religious freedom as a fake, and they claimed to implant “real religious freedom” in its stead. But in making such claims, the occupiers overlooked inconvenient historical facts. Japanese people had been debating the meaning of religious freedom for decades before the Occupation began, and military government records clearly show that the American occupiers were not nearly as certain about how to protect religious freedom as their triumphalist rhetoric suggested. The concepts and governing practices the occupiers developed in collaboration with influential Japanese scholars in the late 1940s still dictate how academics, journalists, and policymakers working today imagine who deserves religious freedom, what kinds of political practices infringe on religious liberty, and who bears responsibility for protecting religious freedom. Focusing on postwar debates about morality education, changes to the Fundamental Law on Education, and constitutional revision, Thomas argues that disagreements about how religion should be defined are central to understanding Japanese political life today.