Translation: high priest fish
Alternate names: umi oshō (sea high priest), irikame nyūdō, kame nyūdō (turtle monk)
Habitat: coastal waters
Diet: probably herbivorous
Appearance: Oshōuo are aquatic yōkai which live in the Sea of Japan off of Fukui and Kyōto Prefectures. They have bodies resembling soft-shelled turtles and smooth, bald heads resembling human monks. The grow up to 150 to 180 centimeters in length.
Behavior: Oshōuo are inauspicious yōkai. They summon strong winds and rainstorms which can result in poor catches or shipwrecks. They also place curses on people who see them.
Interactions: A fishermen who sees an oshōuo or who accidentally catches one should give them an offering of sake and then gently send them on their way. A captured oshōuo will clasp its front legs together as if praying, then begin to cry and beg for its life. In this case, the fisherman should agree to release them after making the oshōuo promise not to curse anyone ever again.
Origin: Oshōuo appear in Edo period encyclopedias such as Wakan sansai zue. They may have been inspired by sightings of sea turtles. They are often considered to be related to umi bōzu.