Mark Cartwright
published on 28 June 2017
Available in other languages: French
Ryujin (by Utagawa Kuniyoshi, Public Domain)
Utagawa Kuniyoshi (Public Domain)

Ryujin (aka Ryu-o) is the dragon king, sea god, and master of serpents in Japanese mythology. With his magic jewels he is responsible for the tides, and he represents both the perils and bounty of the sea and so was especially relevant to an ancient island nation like Japan. Ryujin is often associated with or considered the same as Owatatsumi-no-kami, another water deity or Shinto kami (spirit), better known as Watatsumi. Believed to have a useful knowledge of medicine and considered the bringer of rain and thunder, Ryujin is also the patron god or ujigami of several Japanese family groups.


Ryujin is one of the eight dragon kings which were originally imported from Indian mythology via China and Korea. He is the lord of the sea and snakes, who may be his avatar and which were considered by the ancient Japanese to be a form of dragon. Snakes were also considered the messengers of Ryujin and provide the dragon king with a link to the outside world from his residence in a palace beneath the sea or in the lake of an extinct volcano. The depths of Lake Biwa, north-east of Kyoto, are often cited as Ryujin's home. Snakes were associated with death and thunder which link with Ryujin's role as a bringer of rain and storms. Ryujin was thought to appear in people's dreams and briefly in the moment of waking up. The god of the sea has a handy dispensary of useful medicines, too, especially those which can guarantee a long life. Finally, the god is often linked with sujin, the minor kami of fresh water, springs, and wells.

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The god has shrines across Japan and especially in rural areas where fishing and rains for agriculture are so important for local communities. In art, Ryujin is typically portrayed as a sea-dwelling dragon or a giant snake. He may carry the magic round jewel which represents power and monarchy in Japan and with which the god can control the tides.

Reflecting the fickle nature of the sea, Ryujin can be either a sinister force or a kindLY ruler who helps heroes in distress.

Myths & Heroes

Ryujin is a protagonist in several Japanese myths but, reflecting the fickle nature of the sea, he can be either a sinister force or a kindly ruler who helps heroes in distress. In the guise of Watatsumi, for example, he helped Hoori against the hero's brother Hoderi. However, Ryujin also stole the jewel which belonged to Kamatari, the founder of the Fujiwara clan. The jewel was only retrieved after Kamatari's wife dived down to the god's palace below the sea and took it back, tragically drowning in the process.

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Tawara Toda & the Centipede

In a more flattering story, Ryujin gave a bell (albeit having previously stolen it) to the hero Tawara Toda (aka Fujiwara Hidesato) in gratitude for him saving his palace from a fearsome centipede whose body was so long it covered an entire mountain. The 11th-century CE warrior-hero was famous for his archery skills, but it was not until he magically tipped his fourth and last arrow in his own saliva that he managed to fell the giant creature. The bell was left in the Miidera temple, and it is possible that Ryujin's other gift of a huge inexhaustible sack of rice explains the hero's title as 'Lord Rice Bale' (another reason could be his reputed ability to lift a 60 kilo/132 pound bale of rice). Yet more gifts from Ryujin to Tawara Toda were a magic cauldron that could cook food without the necessity of a fire and a never-ending roll of brocade.


Another myth involving the dragon king is that of Urashimataro. One day the fisherman saw some children tormenting a turtle on the beach and he shooed them away. In gratitude, the turtle offered to take Urashimataro on a sea voyage and a free tour of Ryujin's undersea palace. On arrival the fisherman was given a feast by the dragon king's daughter and, when he finally left, a parting present of a jewellery box. When Urashimataro made it home he saw that the village had changed since he had left, he could not find his own house or his family either. Then he met one old lady who only just remembered being told as a child of the mysterious disappearance of one of the fishermen of the village. On top of that, when he opened his jewellery box a mist came forth that instantly changed him into a very old man with a long white beard. At the bottom of the box was a single feather, and when Urashimataro took hold of it, he was transformed into a crane, the symbol of happiness, which then flew off in the direction of the far away palace of Ryujin.

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Hoori & the Fishhook

Ruyijin, this time as Watatsumi, features prominently in the story of Hoori (aka Hoho-demi or Hikohohodemi) which is told in the Kojiki ('Record of Ancient Things') which was compiled in 712 CE. Hoori, the youngest son of Ninigi (grandson of the sun goddess Amaterasu), one day borrowed the magic fish hook of his brother Hoderi. The hook allowed the user to catch a vast number of fish without any effort at all. Inexplicably, though, when Hoori tried it, the hook would not get a single bite and to make matters worse the hapless fisherman dropped it so that it sank to the depths of the sea.

Not best pleased to find out what had happened to his prize possession, Hoderi refused his brother's offer of a new batch of 500 hooks made from his broken sword. Sitting on the beach in tears, Hoori was approached by a kami who, on discovering his anguish, told him to visit Watatsumi, who would surely be able to find and return the hook if asked nicely enough. Accordingly, Hoori built himself a small boat and after a long voyage finally arrived at the sea god's palace. There he was greeted by Watatsumi's daughter Toyotama-hime and, awestruck by the princess' beauty, promptly forgot why he had sailed there in the first place.

Hoori and Toyotama-hime married with the blessing of Watatsumi who gave them so many gifts it took 100 tables to display them. However, in their blissful youth, they rather lost track of time so that several years passed before Hoori remembered that his brother was still waiting for the fishhook. When he told Watatsumi, the god gathered all the fish in the sea and discovered the hook in the mouth a sea bream (or dorado). He cursed the hook and then gave the departing Hoori two jewels with which he could control the waters that would irrigate his rice fields. Back home after a helpful shark (or crocodile) had given him a lift, the magic jewels ensured that while ruin befell his brother, Hoori became very prosperous and lived for 500 years.

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This content was made possible with generous support from the Great Britain Sasakawa Foundation.

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About the Author

Mark Cartwright
Mark is a full-time writer, researcher, historian, and editor. Special interests include art, architecture, and discovering the ideas that all civilizations share. He holds an MA in Political Philosophy and is the WHE Publishing Director.



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Cite This Work

APA Style

Cartwright, M. (2017, June 28). Ryujin. World History Encyclopedia. Retrieved from https://www.worldhistory.org/Ryujin/

Chicago Style

Cartwright, Mark. "Ryujin." World History Encyclopedia. Last modified June 28, 2017. https://www.worldhistory.org/Ryujin/.

MLA Style

Cartwright, Mark. "Ryujin." World History Encyclopedia. World History Encyclopedia, 28 Jun 2017. Web. 16 Jun 2024.