Umibozu (mononoke)
Romanized Umibōzu
Kanji 海坊主
Kana うみぼうず
Meaning Sea monk
Other names Umi-Nyūdō, Umi-Hōshi
Type Unknown

Umibōzu (海坊主, Umibōzu) is a spirit that lives in the ocean and capsizes anyone's ship who dares speak to it.


Perhaps no other aquatic yokai is as mysterious as the giant umi bōzu. Their true form is unknown, as they are only ever seen from the shoulders up, but they appear to be roughly humanoid in shape, with inky black skin and a pair of large, round eyes. Eye-witnesses report a great range in size, from slightly larger than a ship, to a size so unimaginable that only the creature’s bulbous face is visible above the water. Its head is smooth and round like that of a venerable monk, and its body is nude and as black as shadow. Some reports make them out to be more serpentine, while others make them out to be more ghostly, like a gigantic kind of funa-yūrei.

Umi bōzu appear on calm nights, when there is no sign of anything out of the ordinary. All of a sudden, with no warning, the waves and the weather whip up into a furious condition, and out from the tumult rises a titanic creature. It moves to destroy the ship, either by smashing the hull in a single blow, or taking it down bit by bit, depending on the size of both the ship and the umi bōzu.

Occasionally, instead of smashing the ship, an umi bōzu will demand a barrel from the crew. It uses this to pour huge amounts of water onto the deck, quickly sinking the boat and drowning the crew. If given a barrel with the bottom removed, the umi bōzu will scoop and scoop to no effect, and the sailors will be able to make a lucky escape.

Some say that the umi bōzu are the spirits of drowned priests, cast into the sea by angry villagers (this may also be implied by their name). These priests were then transformed into ghosts due to the horrible nature of their death, making them cousins of the similarly dreaded funa-yūrei, with whom they share some similarities. Others, however, say that umi bōzu are a sea monster which lives in the deeps of the Seto Inland Sea, and that they are the progenitors of a large variety of other aquatic yokai. Because sightings are rare and almost always fatal, it is likely that the true nature and origin of this spirit will remain a mystery for a long time.

In popular culture

  • A traditional Umibōzu folktale is told in the second story arc of the anime Mononoke, a sequel to Ayakashi: Samurai Horror Tales, which combined folktales, Kabuki plays, and animated versions of 19th century woodblock art prints to retell classic ghost stories.
  • Although not a main character, several Umibozu were seen in the fight against the demon in Great Yokai War.
  • The umibōzu is also a monster of the day in the Super Sentai series Ninja Sentai Kakuranger and also appears as Hydro Hog in season 3 of Mighty Morphin Power Rangers in the 10 episode arc Mighty Morphin Alien Rangers.
  • Umi-Bozu is a sub-boss in the arcade video game The Ocean Hunter. Umi-Bozu appear as a giant octopus that can become invisible.
  • The anime One Piece contains a large underwater giant named Wadatsumi, he shares many of the characteristics of a sea bonze and is referred to as such by several of the main characters.
  • In the anime and manga comic City Hunter, Umibozu is a big strong bald character.
  • The manga Ginga: Nagareboshi Gin depicts the strongest dog of Japan, 'Benizakura', who's nicknamed 'Umibōzu' due to the champion's loss of its both ears and therefore resembling the sea monster.
  • The anime Ghost In The Shell: Stand Alone Complex features an elite MSDF special forces unit nicknamed 'Umibozu', wearing dark grey armor and fielding high-end armorsuits.
  • In the anime adaptation of Hanayamata, the character Masaru Ōfuna, a yosakoi goods store owner, is nicknamed 'Umibozu' because of his shaved head.
  • The anime Gintama contains humanoid named 'Umibouzu', known to be the most powerful alien-hunter in the universe.
  • The Waterwraith from Pikmin 2 and the Plasm Wraith from Pikmin 3, both called "Amebouzu" in Japan, have a liquid, translucent form that can not be harmed and chase after the player, according to many theories, crashing their spaceships.
  • The Umibozu appears in Yo-kai Watch. It is depicted as a recolored version of Daidarabotchi.
  • Umibozu appears in Nioh which is a PS4 exclusive video game came out in 2017. It is a boss fight in a mission called "The Ocean Roars Again".


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