This article examines a significant intellectual controversy that occurred in the 1920s over the life and death of Minamoto no Yoshitsune (1159–89), a Japanese legendary warrior from the twelfth century, and its cultural and political significance during the next two decades. In so doing, it illuminates the importance of Yoshitsune, a major figure and a hero of Japan’s premodern era, in the formation of wartime Japanese intellectual history. A key player in these debates was Oyabe Zen’ichirō (1867–1941), an amateur anthropologist and educator of the Ainu, Japan’s indigenous population, who revived the Yoshitsune legends. The enduring popularity of the legends was aided by the numerous cultural adaptations of the legends produced during the 1930s and 1940s. Writers, historians, and artists shifted away from the consistently debated dualism of historical truth that divided scientific and mythic reasoning and found a new meaning of the myths in Japanese intellectual history.