Since ancient times, the Japanese have lived with superstitions of strange presences and phenomena known as "yōkai," creating a culture by turns infused with unease, fear, and divinity. Tsukimono spirit possessions. Fearsome kappa, oni, and tengu. Yamauba crones. Ghostly yūrei. Otherworldy ijin...Where did they come from? Why do they remain so popular? Written by Japan's premier scholar of yōkai and strange tales, this book is both an introduction to the rich imagination and spirituality of Japan's yōkai culture and a history of the authors and writings that have shaped yōkai studies as a field.