In this episode of YOKAI: Exploring Hidden Japanese Folklore, we seek out a mermaid-like yokai, the Himeuo. In the early 19th century, it was said to have appeared in the ocean off Nagasaki Prefecture, one of Japan's few locations of foreign trade at the time. It reportedly warned of the outbreak of illness, but guided that those who drew its form would be saved. What was the significance of this location, and of its piscine form? Yokai researcher Michael Dylan Foster dives into the depths of the Himeuo.