The Isonade (磯撫で, "beach stroker") is an enormous, shark -like sea monster said to live off the coast of Matsuura and other places in Western Japan. [2] According to the Ehon Hyaku Monogatari, its body has never been seen, as it is always "hidden beneath the waves, save for its huge tail fin which is covered in small barbs." [2] . In theory: