Funayūrei are ghosts (yūrei) that have become vengeful spirits (onryō) at sea. They have been passed down in the folklore of various areas of Japan. They frequently appear in ghost stories and miscellaneous writings from the Edo Period as well as in modern folk customs. In the Yamaguchi Prefecture and the Saga Prefecture, they are called Ayakashi. Funayūrei are ghosts believed to use hishaku (ladles) to fill boats with water and make them sink.