A female figure, sometimes considered a type of monster, thought to inhabit mountainous regions. She takes a variety of forms in art and folklore, both benevolent and malicious, and is closely related to some concepts of the Yama no Kami (the deity of the mountains).

As a monster, the yama-uba is a notorious cannibal, her fierce countenance resembling an oni with piercing eyes and a mouth split to her ears. Her more tender form is best known from the tale of Kintarō, where she serves as mother and caretaker to the superhuman child. ¹

Although she is not referred to as a yama-uba, the fierce oni woman of the mountains makes one of her earliest appearances in volume 27 of the Konjaku Monogatari Shū of the Heian Period. This seemingly-kind old woman provides shelter for a young woman who has stolen into the mountains to give birth, but secretly she is a demon who plans to eat both mother and newborn. The would-be victims sneak away while the hag is asleep. ^2,3

The monstrous yama-uba is today best known from such popular folktales as Ushikata Yama-uba (The Ox-Driver and the Mountain Hag) and Meshi Kuwanu Nyōbō (The Wife Who Didn't Eat). In the first tale, a yama-uba harasses an ox-driver who is carrying a load of mackerel through a mountain pass, devouring all his fish, his ox, and eventually pursuing the man himself in order to sate her hunger. The ox-driver manages to outsmart the yama-uba by hiding in the rafters of her hut and pouring boiling water over her as she sleeps. ⁴ In the second story, a man wishes selfishly for a wife who does not eat, and soon finds himself mysteriously wed to such a woman. Although the new bride takes no meals while her husband is home, the food supply mysteriously diminishes. The man spies on his wife and sees her untying her hair so that she can stuff a mouth on the back of her head with riceballs (much like the Futakuchi-onna of the Ehon Hyaku Monogatari), and thus he knows she is a yama-haha. Feigning ignorance, he asks her to leave, but she tricks him and carries him into the mountains inside of a large tub. He manages to escape by hiding in a thicket of iris and mugwort, which blind the yama-haha with their sharp leaves and stems. ⁵

A more positive yama-uba begins to take shape in the Noh play Yamanba. This Noh is believed to be the work of Zeami (1363-1443), an author who considered the human aspect of demons to be essential in their literary depiction, and he writes his mountain hag as a complex embodiment of Buddhist principles rather than a simple fiend of the wilderness. In this play a dancer well-known for her yama-uba-themed performances travels into the mountains and meets the subject of her art. The mountain hag darkens the sky to force the dancer to stay with her for the night, but she only wishes to see a performance and has none of the cannibalistic intentions seen in previous works, and even expresses shame at an old yama-uba story of that nature. The hag expounds on her own nature as neither wholly good nor wholly evil, consistent with the Buddhist notion of non-dualism as seen in the Heart Sutra. ⁶

In the early Edo Period, the yama-uba came to be seen as the mother of Kintarō, the "golden boy" who grew up to be Sakata no Kintoki, one of Minamoto no Raikō's faithful retainers. ⁷ The oldest appearance of the yama-uba in this role is in the Kinpira Tanjōki 公平たんじょうき (1661), in which Kintoki's supernatural derivation is used to explain the demon-like strength of his son Kinpira, who himself has a serpent in woman's form for a mother. ⁸ In Kiyohara no Udaishō 清原右大将 (1677), the yama-uba again appears with a Buddhist nature; she surrenders Kintarō to Raikō as she is seeking release from the cycle of rebirth and can no longer be a mother. Later she appears to Kinpira as an oni woman, ten feet tall and imbued with great supernatural power, and tells him she is watching over him and granting him his great strength. ⁹ In the Zen Taiheiki 前太平記　(c. 1692), the yama-uba is an old woman who explains to Raikō that many years ago she was sleeping atop Mt. Ashigara, when she dreamt that she was making love with a red dragon. Suddenly a clap of thunder jolted her awake, and she found herself miraculously pregnant with Kintarō.¹⁰

Perhaps the most influential version of yama-uba as mother is in the Kabuki play Komochi Yama-uba 嫗山姥, by Chikamatsu Monzaemon 近松門左衛門. In this updated version of the Minamoto no Raikō tales, the yama-uba is young and attractive, a former courtesan named Yaegiri. Her husband has committed suicide in shame, but as he dies sends her to the mountains to live as a superhuman being, who will give birth to a great child to fight alongside Raikō. Raikō adopts Kintarō and in the end they conquer a group of demons threatening the capital.¹¹

The alluring image of the Kabuki yama-uba, coddling her child Kintarō, became a popular subject for ukiyo-e prints, especially with the artist Utamaro. Utamaro's image partially displaced the old image of the yama-uba as demon hag, including that portrayed by his teacher Toriyama Sekien. ¹²

More recently the humane or auspicious yama-uba is seen in the local folklore of various regions, wherein she often helps people with their domestic and agricultural work. In Toyoshina, Nagano Prefecture, she was thought to come to the year's-end market on the 19th and 20th of December. Here she would buy sake using a 3 gō (~.5 liter) gourd which could miraculously hold 5 shō (~9 liters). Her presence would cause the market value to rise, and her leaving would cause it to drop. In the Nishiiyayama area of Tokushima Prefecture, she was known for asking people to carry her on their backs, but also for lending assistance with farming and laundry. In Kōchi Prefecture she was thought to haunt fields and bring about an abundant harvest, but to cause poor harvest and poverty if driven out by those who feared her.

In part of Kyoto, however, it is the yama-no-kami who spreads the seeds of crops and brings about a good harvest, while the yama-uba only spitefully spreads the seeds of thornbushes. ¹⁴

The yama-uba's connection to the mountain deity may be traced back to China, where the Ming Dynasty encyclopedia Běncǎo Gāngmù describes a creature which lives in Lingnan 嶺南 (an area stretching from the southern part of China to Vietnam), which has one leg, a backwards heel, and three fingers on each limb. The female is called shān gū 山姑 and the male shān zhàng 山丈. These are other names for the shān xiāo 山魈, a one-legged mountain demon from Southern China. The Ming Dynasty names for this being can be seen today in Kōchi Prefecture in Japan, as alternate ways of writing the names of the yama-uba and her male counterpart, the yama-jijii. When this is taken with the fact that in older legends, the yama-uba was often described as one-legged, and that the mountain deity of Japanese folk religion is frequently conceived of as a woman, the relationship between the yama-no-kami, the mountain hag, and the shān xiāo becomes obvious. ¹⁴

The yama-uba may have a human background, however, in addition to an exotic demon's pedigree. In the Muromachi-period otogizōshi story, Hanayo no Hime 花世の姫, the yama-uba is simply an old woman who was driven into the mountains by her grandchildren, and Yanagita Kunio observed that yama-uba and yama-hime were euphemisms used by villagers for strange women living in the mountain wilderness. ¹⁵ Belief in the yama-uba's existence may further be tied to ubasuteyama, the custom of abandoning elderly relatives in some remote place during times of hardship, and the hope (or fear) that some lost grandmother might survive and be transformed by a life in the kami's world. ¹

Additional Sources
• Reider, Noriko T. "Yamauba: Representation of the Japanese Mountain Witch in the Muromachi and Edo Periods." International Journal of Asiatic Studies 2.2 (2005): pp. 239-264.

Citations
1. Sasama p. 144.
2. Reider pp. 239-40.
3. Sasama pp. 88-9.
4. Mayer pp. 27-8.
5. Ibid. pp. 26-27.
6. Reider pp. 243-4.
7. Ibid. p. 245.
8. Ibid. pp. 246-7.
9. Ibid. p. 249.
10. Ibid. p. 250.
11. Ibid. pp. 251-2.
12. Ibid. pp. 257-260.
13. Tada 2000 p. 157.
14. Murakami 2005 p. 335.
15. Reider p. 243.