Natsuhiko Kyogoku is a writer and folklore scholar with a deep knowledge of Japanese yokai and supernatural traditions. Born in 1963, he came to publishing almost by accident—he walked into Kodansha with an unpublished manuscript for The Summer of the Ubume and got it accepted, which was unusual enough to catch industry attention. The book's unexpected success actually inspired the creation of the Mephisto Award, a prize specifically designed to find and promote new mystery and fantasy writers.

The Summer of the Ubume became the first in a nine-novel series. The second book in the series won him the Japan Mystery Writers Award in 1994, and he later took home the prestigious Naoki Award in 2004 for Requiem from the Darkness. Fans often note that his background in folklore research sets his work apart, grounding his supernatural stories in genuine cultural knowledge rather than pure invention.