Translation: beach stroker
Alternate names: ōkuchi wani (“giant mouthed sea monster”)
Habitat: shallow seas and coastal waters of West Japan
Appearance: Isonade are mysterious, shark-like sea monsters which scour the rocky coastlines searching for boats to scuttle and fishermen to snatch. Their bodies are enormous, and their fins are covered with countless, tiny metallic barbs like a grater. They use these barbs to hook their prey, dragging them deep into the water to be eaten. Isonade are said to appear when the north winds blow and the sea currents change.
Behavior: Despite their size, isonade are incredibly elusive. They move through the water with unparalleled grace and can swim without creating so much as a splash. This makes them difficult to spot. By the time most sailors have noticed that the winds have changed and a strange color is upon the sea, it is too late—a huge tail is already rising out of the water, above their heads. When isonade strike, they do not thrash about violently like a hungry shark. Instead they hook their prey on their fins or tail with a gentle stroking motion, dragging them into the depths almost peacefully. They do this without a sound and without ever showing their bodies, making them all the more dangerous for their stealth.