Introducing the Kappa: The Mythical River Spirit of Japanese Folklore

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Dive into the origin myth and folklore surrounding the Japanese kappa

Co-authored by Maria Souza and Ali Garbacz, B.A.

Last Updated: May 22, 2025 References

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What is a kappa?

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Origin Story

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Appearance

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Behavior & Disposition

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Representations & Symbolism

Among the many mythical creatures and spirits in Japanese folklore, the kappa is one of the most well-known. This creature, which resembles a reptile and is said to reside in the rivers of Japan, has been a part of Japanese folklore since around the 17th century—possibly even earlier. Depending on which stories you read, the kappa can either be a frightening monster or a mischievous yet well-mannered creature. Read on to learn all about the kappa’s origin, appearance, disposition, and popular stories that it features in.

Things You Should Know

The kappa is a mythical creature from Japanese folklore that primarily resides in rivers. In many myths, it has a scaly, green body, a turtle shell on its back, and a beak for a mouth.
Kappa are depicted as dangerous monsters in some myths and are said to lure people and livestock into the river to feast on their livers.
Other myths depict the kappa as mischievous yet harmless creatures. Some people also view the kappa as water deities rather than monsters.

Section 1 of 5:

What is a kappa?

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The kappa (河童) is a reptilian creature from Japanese folklore. This creature is a type of yokai, which is a term used to refer to eerie phenomena, monsters, demons, and mythological creatures. The kappa are reptilian creatures that are said to live in the rivers and freshwater pools around Japan, and most folklore describes them as harmless, if not a bit mischievous. However, other accounts of kappa suggest that they can also be very dangerous and malevolent creatures at times.^{[1]
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- The word kappa literally translates to mean “child of the river,” and this term originated from the Kanto region of Japan.^{[2]
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- However, there are over 80 regional variations of the kappa, both in its name and attributes. Some examples of different regional terms include kawappa, kawato, kawataro, mizushi, komahiki, and dangam.

Section 2 of 5:

Kappa Origin Story

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A carpenter made straw dolls that transformed into the kappa. This story has many variations, but a simplified version tells the tale of a carpenter who created dolls made out of straw and breathed life into them so that they could help him with his work. Once he no longer needed the dolls, he tossed them into the nearby river where they transformed into the kappa, therefore giving an explanation as to why the kappa reside in the water.^{[3]
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- Some depictions of the kappa describe it as having the ability to slide its arms smoothly from left to right. This is because it was transformed from a straw doll that had a single piece of bamboo stuck through its middle to make a pair of arms.
- While the exact origin of the kappa is unknown, it’s made an appearance in Japanese folklore since the Edo Period (1603-1867), and possibly even earlier.

Section 3 of 5:

Kappa Appearance

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The kappa are the size of a small child and have scaly skin. The exact height of the kappa isn’t explicitly stated, and most stories simply describe the creature as being around the same size as a young child. The kappa is described as having some similar physical traits to reptiles and amphibians, including scales along their bodies, webbed hands and feet, and a hard shell on their back. They’re usually depicted as being green in color.^{[4]
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- However, there are many different variations when it comes to the physical description of the kappa. For example, instead of scales, some stories describe the kappa as being hairy all over their body and resembling a monkey more than a reptile.
- Many stories claim that the kappa have a very fishy smell, and some even say that the creature passes incredibly smelly gas.^{[5]
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Most kappa have a beak-like mouth. In terms of its facial structure, kappa are usually described as having very sharp faces and a beak for a mouth. In some variations of these myths, it’s said that the kappa are incredibly intelligent and can speak, despite having a beak instead of a typical human mouth.^{[6]
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- Some accounts of the kappa describe its face as being blue-black in color instead of green or blue like the rest of its body.
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A kappa has a cavity on top of its head that holds water. This is one characteristic that appears in most depictions of the kappa. This cavity, known as the sara (皿), is usually in the shape of a small bowl or dish, and the water inside is often thought to be the kappa’s source of power. According to certain myths, if a kappa loses the water in this cavity, it loses its powers or can even die.^{[7]
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- In some variations of the kappa myth, these creatures actually have a small metal dish on top of their head instead of just a cavity.
- Other accounts of the kappa don’t specifically say that this cavity contains water and simply describe its contents as being a liquid of some sort.

Section 4 of 5:

Kappa Behavior & Disposition

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It’s said that kappa drown children and livestock in rivers. Many myths claim that the kappa does this in order to eat the liver of their victims. They do this by sucking out an imaginary, ball-shaped organ called the shirikodama (尻子玉), which is found in the anus. This behavior of the kappa is what gives it its dangerous and malevolent image, and children are warned by their parents to stay away from the water.^{[8]
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- Some stories revolving around kappa claim that the removal of a person’s shirikodama will cause them to die, with certain variations stating that this imaginary organ contains a person’s soul or spirit.^{[9]
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- Other stories show the kappa targeting adult humans as well as children.
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Some kappa are mischievous and enjoy sumo. While many stories speak to the kappa’s dangerous nature, other myths paint this creature as being rather playful and a bit foolish at times. One example of this is their love for the sport of sumo, a type of full-contact wrestling. Many stories involve them challenging passersby to a sumo match.^{[10]
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- In one such story, a group of children is playing by the river when an unknown child approaches them and challenges them to a sumo match. The children realize that the other child is actually a kappa, and, to get the creature to leave, they shake their heads. The kappa copies their actions, causing the water on top of its head to spill out and forcing it to leave.^{[11]
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- Kappa are known to be quite polite, so a trick to defeating them when challenged to a sumo match is to simply bow. They’ll likely return the gesture and end up spilling the water on top of their heads.
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The kappa love cucumbers. The association between kappa and cucumbers gives another look into their dual images and representations. According to some legends, if a person eats a cucumber and goes swimming right after, they’ll most certainly be attacked by a kappa. However, other people view the kappa as a deity rather than a monster, and so offer up cucumbers during festivals associated with this creature.^{[12]
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- Other foods that the kappa likes include Japanese eggplant, fermented soybeans, and pumpkin.
- However, kappa have a strong aversion to gourds, and these vegetables are said to be a way to confound and drive away kappa according to some myths.
- For example, the “kappa bridegroom tale” tells the story of a farmer who offered up his daughter for marriage to anyone who was able to irrigate his dried-up fields. A kappa succeeded in this task and therefore received the farmer’s daughter as its bride. However, the daughter challenged the kappa to sink gourds in the river, eventually leading to the creature abandoning the marriage since it couldn’t accomplish the task.
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The kappa are also honest and benevolent creatures. Contrary to the stories that depict them as violent water monsters, many stories also paint kappa as being mischievous but harmless. For example, many stories narrate the kappa’s attempts to lure people or livestock into the river, but ultimately failing and having its arm yanked off or being weakened due to water spilling from the cavity in it head. When this happens, the kappa will pledge an oath in order to be set free or get its arm back.^{[13]
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- For example, one legend states that a kappa actually taught the practice of bone-setting to the Japanese as part of its oath, along with other medicinal practices.
- Other stories mention how kappa will often continue to leave fish for their captors after seeing their oath through and being set free. These kinds of legends paint the kappa in a much more positive light, and some people believe that a fish offering from a kappa is a sign of good luck.

Section 5 of 5:

Representations & Symbolism of Kappa

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Some view kappa as water deities. For those who hold a more positive view of kappa, they consider these river spirits to be deities linked to the river, fertility, and bountiful harvests. This view is held by some people who practice Shinto Buddhism, and there’s a tradition of leaving cucumbers at Shinto shrines to appease these water deities.
- Some believe that the kappa split their time between the river and mountains, spending autumn and winter as a yama no kami (山の神, mountain god), and spring and summer as a mizu no kami (水の神, water god).
- Thus, there are traditions that revolve around ushering the kappa in and out in its various forms to ensure a good harvest and fertility during the growing seasons.
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Some view kappa as representations of human nature. The original folklore surrounding the kappa used the creature as a means to explain natural phenomena and concepts that were outside of the human realm. However, the publication of writer Akutagawa Ryunosuke’s short story “Kappa” in 1927 saw more human-like traits and thoughts being given to the character of the kappa. After that, people began to associate the kappa with the human world rather than just the supernatural and mystical realm.^{[14]
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- More people began to depict the kappa in more typical human environments and situations through cartoons, drawings, and stories. For example, cartoonist Shimizu Kon depicted the kappa as a creature that works to make a living and lives a rather ordinary life in the comic “Kappa tengoku” (“Kappa Heaven”).
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The benevolent image of kappa is more popular in modern times. Instead of a scary, predatory reptile, modern depictions of the kappa have transformed it into something much cuter. The kappa is one of the most well-known yokai in Japanese folklore, and it’s been featured in numerous cartoons, animated movies, and games, usually as a more peaceful and friendly version of its form from traditional folklore.^{[15]
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- For example, Tokyo Mitsubishi Bank uses the kappa as the mascot for its DC credit card and gives it a very cartoonish and cute appearance.
- Kappa-inspired creatures have also appeared in video games, including the Animal Crossing and The Legend of Zelda series.