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TRANSLATION: shark person
HABITAT: oceans; particularly the South China Sea
DIET: carnivorous

APPEARANCE: Kōjin are aquatic humanoids that closely resemble ningyo. Unlike the merfolk of Western legends, Asian merfolk are monstrous in appearance. Kōjin have black, scaly shark-like bodies, and ugly, human-like facial features and arms.

BEHAVIOR: Kōjin are native to the South China Sea, where they live a life similar to other merfolk. They are well known for their skill at weaving, and they spend much of their lives working on their looms. The sea silk that they weave is of the finest quality and doesn’t get wet even in the water. They are very emotional, and cry frequently. When they cry, pearls (or precious gems, by some accounts) fall from their eyes instead of tears.

ORIGIN: The kōjin is better known in the West by the alternate reading of its kanji—samebito. This is because of Lafcadio Hearn, who included a story about a samebito in his book of Japanese folk tales, Shadowings.

LEGENDS: Long ago, a man named Tawaraya Tōtarō lived on the shore of Lake Biwa. One day, he came across a strange looking creature crouching near the base of a bridge. It resembled a man, but its body was inky black, it had the face of a demon and the beard of a dragon, and its eyes were like green emeralds. Although Tōtarō was scared, the green eyes seemed gentle to him, and so he approached the creature. The creature introduced himself as a samebito. He had served as an officer under the Eight Great Dragon Kings in the dragon palace of Ryūgū-jō, but was banished from the palace and exiled from the sea due to a small mistake he had made. Since then, he had been wandering, unable to find food or shelter. He begged Tōtarō for help.

Tōtarō pitied the samebito. He took the samebito back to his home, where he had a small garden with a pond. He told the samebito that he could live there for as long as he wanted, and he could have as much food as he wanted to eat. For six months they lived together, and every day Tōtarō brought the samebito fresh food fit for a sea creature.

During the seventh month, Tōtarō went to a festival at Mii-dera, where a great pilgrimage of women had come. There, he met a woman of extraordinary beauty and refinement, with skin as white as snow, and a voice like a nightingale. Her name was Tamana, and Tōtarō fell in love with her at first sight. Totaro followed Tamana home, and discovered that she lived in the same town in which he had met the samebito. He also learned that she was unmarried, and that her family wanted her to marry a man of rank. They demanded as a betrothal gift a casket of ten thousand jewels from whomever wished to marry Tamana.

Tōtarō fell into despair, knowing that even if there were ten thousand jewels in all of Japan, he would never be able to procure them. Though it seemed impossible that he could ever make Tamana his wife, he could not get her lovely face and sweet voice out of his mind. It haunted him so much that he refused to eat or sleep, and became so ill that he could not even lift his head from his pillow. It seemed that he would die of a broken heart. The samebito, whom Tōtarō had cared for in his time of despair, entered the house to care for Tōtarō in his last days. Tōtarō apologized to the samebito, fearing that after his death, the samebito would lose his home and his means of survival, and would die as well. The samebito was so touched by Tōtarō’s compassion that he began to cry. Great tears of blood spilled from his green eyes and down his black cheeks, but by the time they hit the floor they had hardened into splendid rubies.

At this sight, Tōtarō instantly found new strength, and began to gather the jewels. The samebito, astonished at Tōtarō’s recovery, stopped crying. Of course, the flow of jewels also stopped. Tōtarō begged the samebito to continue crying until he had ten thousand jewels, but the samebito regretfully replied that he could only weep when he felt true grief in his heart. Seeing that Tōtarō’s sickness was cured, the samebito was filled with nothing but relief, and thus could not cry anymore. The samebito suggested that they visit the bridge where they had first met to reminisce, and perhaps he could cry again.

The next day, Tōtarō and the samebito visited the bridge. They ate fish and drank wine, and watched the setting sun. Seeing the sun set over the sparkling sea, and with a little help from the wine, the samebito thought about his former life in the sea and his happy days in the dragon palace. He was overcome with homesickness and began to weep profusely. A great shower of jewels covered the bridge. Tōtarō began gathering them up. When he had collected ten thousand jewels he shouted for joy. At the same moment, a delightful song was heard far away in the sea. Like a cloud, a glorious palace made of coral the color of the setting sun rose out of the water. The samebito leaped with joy. He explained to Tōtarō that the Eight Great Dragon Kings must have granted him amnesty and were calling him back home. He bade his farewell to Tōtarō, thankful for his kindness and their friendship, and then dove into the sea.

Tōtarō never saw the samebito again. He brought the casket of ten thousand jewels to Tamana’s family and presented them as a betrothal gift. Shortly after, Tōtarō and Tamana were married.



TRANSLATION: white-spotted char; literally “rain trout”
HABITAT: cold streams and lakes, occasionally seagoing
DIET: carnivorous, ranging from small fish and plankton up to and including large boats

APPEARANCE: Amemasu is the Japanese name for the white-spotted char (Salvelinus leucomaenis leucomaenis), a species of trout which is found in Northeast Asia. They are a popular target of game fishing and are also raised in fisheries.

BEHAVIOR: Amemasu spend most of their lives in the water, away from humans. They are found mostly in rivers and streams, but seagoing varieties exist as well. They are more common in Hokkaido, the northern parts of Honshu, and along the Sea of Japan—however legends of amemasu are occasionally found in the southern parts of Japan as well. They feed on whatever they can eat—from plankton to insects, to fish and any other aquatic lifeforms they can fit into their mouths. Yōkai amemasu can grow to colossal sizes, sometimes spanning an entire lake from head to tail. These giant amemasu also occasionally thrash and sink ships, devouring any poor souls who happened to be on the ship. In Ainu folklore, the wild thrashing of giant amemasu is believed to be what causes earthquakes—much like giant catfish are thought to cause earthquakes in the rest of Japan.

INTERACTIONS:  Amemasu can transform into human shape and walk about on land. They usually take the form of young, beautiful women in order to seduce young men. Shape-changed amemasu can be identified by their skin, which feels cold and clammy like that of a fish.

LEGENDS: A number of lakes in Hokkaido are believed to be the home of giant amemasu. According to Ainu folklore, these amemasu are thought to be the guardian deities of their respective lakes. Lake Mashū is home to an amemasu the size of a whale. Lake Shikotsu contains an amemasu so large that its head touches one end of the lake and its tail touches the other.

A legend from Minabe, Wakayama Prefecture tells of a mysterious whirlpool that appeared in a deep pond. A giant amemasu lived in the pond. Every spring, she would emerge from the pond in the form of a beautiful woman. For two or three days she would catch young men and take them away—where to nobody knows, but they were never seen again. The only way to know that it was a fish and not a woman was from her cold, clammy skin. One day, a cormorant dove into the pond to go hunting. The giant amemasu swallowed the bird in a single gulp. However, after a short time, the amemasu’s body floated up to the surface of the pond, dead. The cormorant burst out of its stomach. A shrine was built at that spot to honor Konpira-san, which still stands today.



TRANSLATION: none; just the name for this monster
ALTERNATE NAMES: ayakashi, ikuji
HABITAT: open seas
DIET: unknown; but it is big enough to eat anything it wants

APPEARANCE: Ikuchi are colossal sea monsters that roam the open seas off the coasts of Japan. They appear in numerous stories from the Edo period, where they are described as enormous fish or monstrous serpents of some kind. Their bodies are covered in a slippery oil, which sheds as they swim the ocean.

INTERACTIONS: When an ikuchi’s path crosses a boat’s, the sea monster envelopes the boat in its tentacle-like body. It slithers over the sides and across the deck, slowly sliding its whole body over the boat. Ikuchi are so long—many kilometers, by some accounts—that it can take hours for an entire one to slither over a boat. On a few occasions, boats have been tangled up in this monster for days. During this time, sailors must constantly bail the monster’s oily slime off of the deck to avoid being capsized by the heavy goo.

ORIGIN: An ikuchi is depicted in Toriyama Sekien’s bestiary Konjaku Hyakki Shūi, where it is called ayakashi. This yōkai is often referred to by that name. Ayakashi is more commonly used as a term for other strange creatures and supernatural phenomena and has nothing in particular to do with ikuchi. Toriyama Sekien may have just been listing the ikuchi as an example of an ayakashi. For whatever reason the name stuck.




TRANSLATION: giant catfish
ALTERNAtE NAMES: jishin namazu (earthquake catfish)
HABITAT: rivers, seas, oceans, and subterranean caverns
DIET: omnivorous

APPEARANCE: As their name suggests, ōnamazu are gigantic catfish which live in the muck and slime of the waterways around Japan. They also inhabit large caverns deep underground.

BEHAVIOR: Ōnamazu behave much like their smaller cousins. They dig in the muck, and thrash about when disturbed or excited. Due to their titanic mass, the thrashing of ōnamazu is considerably more violent than ordinary catfish, to the point where they are dangerous to humans. When these monstrous fish get excited, they shake the earth with their violent thrashing, causing devastating earthquakes in the areas near where they live.

INTERACTIONS: Ōnamazu do not normally interact with people, however during the Edo period they were popularly depicted in newspaper illustrations. Usually these pictures showed a huge, grotesque catfish being subdued by a large number of people, gods, or even other yokai, desperately trying to calm its thrashing.

ORIGIN: Long ago, common belief was that earthquakes were caused by large dragons which lived deep in the earth. During the Edo period, the idea of catfish causing earthquakes gradually began to displace dragons in popular lore as the origin of seismic activity. By the 1855 Great Ansei Earthquake, the ōnamazu had become the popular culprit to blame for earthquakes. This was due mostly to the hundreds of illustrations of thrashing catfish which accompanied newspapers reporting the news of that disaster. They were so popular they spawned an entire genre of woodblock print: namazu-e (catfish pictures).

The reason catfish came to represent earthquakes was due to a large number of witnesses observing catfish behaving oddly—thrashing about violently for seemingly no reason—just before the earthquake. Rumor quickly spread that that catfish had some kind of ability to foresee the coming disaster. Since then, the catfish has regularly appeared as a symbol for earthquakes—either as the cause or as a warning sign of the coming disaster. Recent studies have shown that catfish are in fact very electrosensitive and do become significantly more active shortly before an earthquake hits—showing that there is more to this myth than meets the eye!

LEGENDS: The Kashima Shrine in Ibaraki prefecture is the source of a famous story about ōnamazu. The deity of the shrine, a patron deity of martial arts named Takemikazuchi, is said to have subdued an ōnamazu. He pinned it down underneath the shrine, piercing its head and tail with a sacred stone which still remains in the shrine today—the top of the stone protrudes from the ground. Earthquakes that take place during the 10th month of the lunar calendar—”the godless month,” when the gods all travel to Izumo—are said to be due to Takemikazuchi’s absence from the shrine.

During the 2011 Tōhoku disaster, the Kashima Shrine was badly damaged by an earthquake. The large stone gate was destroyed, stone lanterns were knocked down, and the water level in the reflecting pond changed. The gate was rebuilt in 2014.



TRANSLATION: coated Buddha
HABITAT: poorly cared for family altars, run-down homes
DIET: none

APPEARANCE: Nuribotoke is a kind of grotesque zombie which creeps out of a butsudan that has been accidentally left open at night. It is a soft, flabby corpse-like spirit with oily black skin and a pungent smell. Trailing behind is a catfish-like tail connected to its spine. The most striking and disturbing feature is this spirit’s eyeballs, which dangle wildly from its eye sockets.

INTERACTIONS: Nuribotoke do not do much other than fly about, flapping their tails, and terrorizing the families whose butsudan they crawled out from. They dance about impishly, reveling in their ability to terrorize the living. Occasionally they try to trick foolish humans by giving false prophecies. They can be kept at bay by sprinkling salt on the floor, which they will avoid crossing. Nuribotoke return to their butsudan before sunrise, and they vanish altogether during the day. However, it is best to prevent their appearance altogether by never leaving a butsudan open at night.

ORIGIN: In most Japanese homes there is a large ornate wooden shrine called a butsudan. Inside are religious icons, scrolls, mantras, statues, and other holy items. It serves as the center of household spirituality, and the ancestors of a family are all enshrined in it. During the day, the butsudan stays open, and during holidays and special occasions it is treated like a member of the family, with offers of food and sake given to it. The doors to a butsudan are always closed at sunset; the butsudan is a gateway to the spirit world, and superstition warns that if it is left open at night, certain spirits can wander freely back and forth between the land of the living and the land of the dead. Nuribotoke is one of these spirits.



TRANSLATION: beach stroker
ALTERNATE NAMES: ō-kuchi-wani (giant mouthed sea monster)
HABITAT: shallow seas and coastal waters of West Japan
DIET: carnivorous

APPEARANCE: Isonade are mysterious shark-like sea monsters which scour the rocky coastlines searching for boats to scuttle and fishermen to snatch. Their bodies are enormous, and their fins are covered with countless tiny metallic barbs, like a grater. They use these to hook their prey, dragging it deep into the water to be eaten. They are said to appear when the north winds blow and the sea currents change.

BEHAVIOR: Despite their size, isonade are incredibly elusive. They move through the water with unparalleled grace. They can swim without creating so much as a splash, making them very difficult to notice. By the time most sailors have noticed that the winds have changed and a strange color is upon the sea, it is too late; a huge tail is already rising out of the water, above their heads. When isonade strike, they do not thrash about violently like a hungry shark, but instead hook their prey on their fins or tail with a gentle stroking motion, dragging them into the depths almost peacefully. They do this without a sound and without ever showing their bodies, making them all the more dangerous for their stealth.



TRANSLATION: human fish; mermaid, merman
HABITAT: seas, oceans, and other large bodies of water
DIET: omnivorous; fish, seaweed, and other aquatic foods

APPEARANCE: Mermaids are known as ningyo in Japanese, but they are very different from the mermaids of Western tradition. Ningyo more closely resemble fish than humans, with a varying level of human-like features, ranging from just an ugly, deformed fish-like face, to an entire human torso with long, bony fingers and sharp claws. They can range in size from the size of a human child to the size of a large seal. Unlike the mermaids of the Atlantic and Mediterranean legends, ningyo from the Pacific and the Sea of Japan are hideous to behold, resembling more of an otherworldly nightmare than a seductive siren.

Mermaids resembling the breeds known throughout the West – with an attractive human torso and a piscine lower body – are not unheard of in the Japanese islands. Particularly since the end of the Edo period and the opening of Japan to the West, more and more Western-style Atlantic mermaids have been seen in Japanese waters. However, the most common Japanese mermaid is more beast than beauty.

INTERACTIONS: Ningyo sightings go back to the earliest written histories of Japan. The first recorded mermaid sightings in Japan are found in the Nihon Shoki, one of the oldest books of classical Japanese history, dating back to 619 CE. The flesh of a ningyo is believed to grant eternal life and youth to those who eat it, and thus it is the subject of many folk tales. However, it carries with it a danger that most people are not willing to risk. Ningyo can place a powerful curse on humans who try to wound or capture them, and some legends tell of entire towns that were swallowed by earthquakes or tidal waves after a foolish fisherman brought home a ningyo in one of his catches. While their grotesque appearance and supernatural powers make them an intriguing subject, they are best avoided at all costs.