Tradition: Japanese Mythology
Alternative Names: –
Category: Mountain dweller

The Myth

Omoshiro is a mysterious supernatural presence associated with a strange cry heard in the mountains of Tōno, Japan. Its appearance is unknown, and it is remembered chiefly for a startling voice that echoes through a secluded valley beneath the moonlight.

One moonlit night, a young man named Kikuchi Yanosuke was crossing Sakaiki Pass with his companions on the way to the coast. As they passed through Ōtani-chi, a deep valley filled with birch trees, thick vegetation, and a stream below, Yanosuke played his flute. Suddenly, a voice rang out from the bottom of the valley, shouting, “Interesting!” The men were overcome with fear, turned pale, and fled.

Yanosuke later experienced another strange event in the mountains, when he heard a woman’s scream. At the same time, his sister was being murdered by her own son. The connection between these events remained mysterious, leaving Omoshiro as an unexplained presence associated with eerie voices, fear, and ominous happenings in the mountains.

Sources

“Omoshiro.” 新版TYZ 妖怪図鑑 (New TYZ Yokai Encyclopedia). https://tyz-yokai.blog.jp/archives/1074589312.html

Tradition / Region: Japanese Mythology
Alternate Names: Oni-doku
Category: Mountain dweller

The Myth

On the thirteenth day of the eighth month in the second year of Kan’en (1749), a strange and terrifying event took place in Soma County of Hitachi Province.

Atop Mount Masakado stood an ancient pine tree. It was said to have grown there since the days of Taira no Masakado, its roots gripping the mountain for generations. But that year, long and relentless rains soaked the land. The mountain soil eroded, and floodwaters rushed down its slopes, exposing the roots of the old pine. Then a fierce wind arose and toppled the great tree from its base.

When the pine fell, something was revealed beneath its roots.

Buried in the earth lay a monstrous being—what people called a “Kidoku,” a Demon Slayer, though no one knew its true nature. As the rain beat down upon it, the creature awoke and began to scream.

Its cries echoed across the castle town below. The sound was so dreadful that men, women, and children alike were seized with terror. Some collapsed where they stood. Others fled indoors, covering their ears. The wailing did not cease.

The castle’s commander gathered a rifle squad and marched to the mountain. The creature, fully exposed now, writhed and shrieked beneath the fallen pine. It was immense—said to be the size of eight tatami mats laid side by side.

Those who saw it described a form like a monstrous ogre mixed with a crab. Its eyes were round and bowl-like, shining with an eerie light. The top of its head was sunken inward. Crimson hair, stiff and sharp like palm leaves, bristled from its scalp, and beneath its chin grew spiky strands like thorns. Its teeth were bared in rage.

The riflemen fired again and again. After several shots, the monster finally fell silent.

Thus the Kidoku was slain, and the mountain returned to stillness. But people long remembered the day when the ancient pine fell, and a screaming demon rose from the earth beneath its roots.

Sources

tyz-yokai.blog.jp contributors. (n.d.). Kidoku. In tyz-yokai.blog.jp, from https://tyz-yokai.blog.jp/archives/1077741605.html

Tradition / Region: Japanese Mythology
Alternate Names: Gurannumono no Kai
Category: Mountain dweller

The Myth

In the mountains of Tohoku there is said to dwell a vast and terrible being known as the Grand Mononoke.

Long ago, in a remote region whose name was later said to echo that of a foreign missionary who once passed through during the Azuchi–Momoyama period, strange rumors began to spread. Shepherds whispered of livestock vanishing without a trace. Hunters spoke of something immense moving through the forest with unnatural speed. Yet no ordinary beast could have done such things.

The creature was described as a fusion of many spirits, as if the mountain itself had gathered its most fearsome yokai and bound them into one body. It stretched ten meters in length. Its form seemed to combine the long coils of a giant serpent, the cunning face of a shapeshifting cat, the features of a tengu, and the watery hints of a kappa. It was neither one thing nor another, but a union of spirits.

Despite its enormous size, the Grand Mononoke moved swiftly. When hunger stirred it, it descended from its hidden lair to seize cattle or horses, carrying them off into the forest to be devoured. These attacks were rare but unforgettable.

Most of the time, however, it remained secluded deep in the mountains. It did not wander openly, nor did it terrorize villages without reason. Because of its reclusive nature and overwhelming presence, the people came to regard it not only with fear but with reverence. Some believed it was no mere monster but a mountain god in a terrible form. Offerings were made in quiet places. Prayers were whispered to appease it.

Thus the Grand Mononoke became a hidden sovereign of the high peaks—an emperor of demons who ruled unseen, dwelling in shadow, appearing only when the balance between humans and the wild was disturbed.

Sources

tyz-yokai.blog.jp contributors. (n.d.). Grand Mononoke. In tyz-yokai.blog.jp, from https://tyz-yokai.blog.jp/archives/1073956690.html

Tradition / Region: Japanese Mythology
Alternate Names: Yamajijii, Yamachiji, Yamajichi
Category: Mountain dweller

The Myth

Yamaji is a mysterious mountain monster found in the folklore of Kochi Prefecture and other parts of Shikoku, Japan. It usually appears as a tall or thin old man, sometimes with only one eye and one limb. In some accounts, it has two eyes, but one is so tiny that it can barely be seen. Its strange, human-like appearance conceals a dangerous supernatural nature.

Yamaji is said to possess the ability to read human thoughts. Like the Satori creatures of other Japanese legends, it can anticipate what a person is thinking and respond before they speak. However, people can sometimes defeat it through cleverness and unexpected tricks.

One tale tells of a man who encounters Yamaji in the mountains and is challenged to a contest of shouting. The monster produces such a tremendous roar that the trees tremble and stones move. To defeat it, the man pretends to shout loudly before secretly firing a gun beside the creature’s ear. Startled by the sudden noise, Yamaji believes the man has won the contest and loses the challenge.

But the monster does not easily forget a humiliation. After discovering the trick, it disguises itself as a spider and sneaks into the man’s home to take revenge. Other stories describe Yamaji harming people and horses, invading houses in disguise, and appearing alongside the fearsome mountain witch known as Yamauba. In some legends, Yamauba even comes to avenge a Yamaji that has been defeated.

Yamaji is a dangerous spirit of the wilderness, combining the appearance of an old mountain hermit with supernatural intelligence, tremendous strength, and a talent for deception. Its tales warn travellers that the mountains may conceal beings who understand human thoughts but can still be outwitted by a quick and cunning mind.

Sources

TYZ-Yokai Blog contributors. (n.d.). 山爺 (Yamajiji). In TYZ-Yokai Blog, from https://tyz-yokai.blog.jp/archives/1077741578.html

Tradition / Region: Japanese Mythology
Alternate Names: Kidnapper Jizo
Category: Mountain dweller

The Myth

Long ago, a master marksman, said to be the finest shooter in all of Japan, lost his way while traveling through the mountains. As night fell, he noticed a single house glowing with lamplight and went inside, hoping to find shelter.

Within the house he found a young girl sitting alone, weeping. When he asked what troubled her, she told him of a dreadful fate that haunted the village. Each night at midnight, a mysterious being came to take one villager away. No one knew where they were taken, and now the turn had fallen upon her.

The marksman told her not to fear. He hid the girl inside a closet and resolved to face the creature himself. Through the long night he waited, motionless. Then, at exactly three in the morning, a heavy thud echoed from the doorway. In that instant, the marksman fired his gun.

At dawn, he stepped outside and froze. Standing before the house was a Jizō statue, spattered with blood.

The statue spoke. It said that it had never wished harm upon the villagers. Long ago, it had asked only for a roof to protect it from rain and dew, but no one had built one. Left exposed to the elements year after year, it had decided to repay the neglect by taking the villagers away, subjecting them to the same suffering it endured. Yet it insisted that none had been killed.

The Jizō declared that if the villagers purified themselves and repented, all would be set right. When this was done, the statue raised its left hand, and the missing men returned. When it raised its right hand, the women emerged, unharmed.

Ashamed of their neglect, the villagers begged forgiveness. They built a fine shrine for the Jizō and enshrined it with care and reverence. From that time on, the kidnappings ceased, the harvests were plentiful, and the village prospered.

Thus Hito-jizō remained—not as a kidnapper, but as a reminder that even silent spirits must be treated with respect, lest neglect turn guardians into judges.

Sources

TYZ-Yokai Blog contributors. (n.d.). ヒト地蔵 (Hito-Jizō). In TYZ-Yokai Blog, from https://tyz-yokai.blog.jp/archives/1077383013.html

Tradition / Region: Japanese Mythology
Alternate Names: Demon of Mount Jubusen
Category: Mountain dweller

The Myth

Long ago, a man and his companion set out on a pilgrimage to Mount Jubusen. They climbed the mountain together, following the sacred paths until the day began to fade and dusk crept across the peaks. As evening fell, they turned back toward the descent, eager to leave the mountain before darkness fully claimed it.

As they looked toward a distant summit, something unnatural appeared in the sky. Riding upon a cloud, a strange being rose into view. Its form was half-hidden in the mist, its lower body swallowed by the cloud itself, while its upper body loomed above it. The creature lifted its arms and breathed fire as it drifted through the air, moving toward them from the far peak.

The sight struck the two travelers with terror. Without thinking, they fled in panic, tumbling and rolling down the mountain slope as fast as they could, desperate to escape the approaching presence. They did not look back, nor did they stop until they were far from the heights of Mount Jubusen.

No further encounter is recorded, and no explanation is given for what the creature truly was. It is remembered only as a terrifying apparition of the mountain—an omen glimpsed at twilight, rising from cloud and flame, reminding those who walk sacred peaks that not all beings there welcome human eyes.

Sources

TYZ-Yokai Blog contributors. (n.d.). ジュブセン奇怪 (Jubusen-Kikai). In TYZ-Yokai Blog, from https://tyz-yokai.blog.jp/archives/1074775095.html