Traditional Yokai Encyclopedia

A representative form from the Tokaido’s Sayo no Nakayama. The spirit of a pregnant woman murdered on her journey is said to have possessed a stone and cried each night for her unborn child. People performed memorial rites, and in time the spirit was soothed. Folklorically, it is tied to roadside memorials, Koyasu child-protection faith, and the erection of stone steles, reflecting an older belief that spirits dwell within stones.

This version turns to how the Yako was spoken of in the Buddhist world, and in Zen in particular. Zen has the term yako-zen, "wild-fox Zen." It is a word of admonition for a half-finished state in which one has not truly attained enlightenment yet believes oneself enlightened. Its source is the famous tale "Hyakujō and the Wild Fox," recorded in the Song-dynasty Zen collection of dialogues, the Mumonkan. An old man came to listen each time the Tang Zen master Baizhang Huaihai (Hyakujō Ekai) preached. One day the old man revealed his story. Long ago, when he had been abbot of this very temple, he was asked whether one who has attained enlightenment still falls subject to cause and effect (karmic retribution), and he answered, "He does not fall (into cause and effect)." For that single mistaken word he had been cast into the body of a wild fox through five hundred rebirths. The old man begged Hyakujō for the correct answer. When Hyakujō rephrased it as "He does not obscure cause and effect," the old man was freed of his delusion on the spot, shed the wild-fox body, and attained buddhahood. Here the wild fox becomes a symbol of admonition—the form into which one who has fallen into half-baked enlightenment is transformed. Quite apart from the village field fox that deceives people, the Yako has lived on at length within the language of Zen as well, as "where shallow cleverness ends up."

Yamabiko is the personification of echoes in the mountains, interpreted as a kodama or a retainer of the mountain deity. Its habit of repeating words back is seen as a boundary-marking reply within the mountain domain, warning against reckless shouting that disrupts the mountain’s vital energy. Early modern images depict it as a small beast akin to a dog or monkey; figures in Hyakkai Zukan and Gazu Hyakki Yagyō have been linked to the yama-ko in Wakan Sansai Zue and to Penghou, said to dwell within trees. Depending on region, intermediaries vary—bird calls like the yobukodori or resonant rocks such as “Yamabiko Rock.” Phenomenon, spirit, and monster imagery overlap in layered tradition.

This version builds on a record narrative centering on the Miyoshi anomalies of Kan’en 2. The chieftain declares himself in samurai guise at the close of the thirty days of hauntings, mentioning a wager with Kamino Akugorō. He states he is neither tengu nor fox spirit, yet some paintings depict him as a three-eyed crow-tengu, revealing a gap between text and image. Across manuscripts his name varies—Yamamoto Gorōzaemon, Yaman-moto Gorōzaemon, Yamamoto Tarōzaemon—and in alternate strands he bestows different gifts, such as a mallet or a scroll of rites. Around Miyoshi, multiple “trial of the brave” tales persist, sharing a sequence of fixed-term hauntings, the master of the house remaining unshaken, the leader’s appearance and words of praise, and a token left upon departure. His concrete nature and origin remain unsettled, while his role as a demon-king-like commander is emphasized. Given differences among early modern essays and picture scrolls, proper names and details should be treated as variant by text.

A reconstruction guided by Sekien Toriyama’s image and notes. The head resembles a grater, its surface studs likened to porcupine quills. Though written as “Yamaoroshi,” its nature is not a mountain wind itself but an abstract monster born from combining a utensil (grater) with a bestial image. Daikon radishes and mortars placed nearby signal a tsukumogami-style scene, with no specific harm or blessing described. Rooted in Edo-period paintings, it lacks regional oral lore or cult, and later handbooks often present it as an example of utensil transformation and wordplay.

Orochi is more than a snake. The old word orochi is often explained as combining a term for peak or ridge with chi, a word for spirit-power. The Kojiki describes moss, cypress, and cedar growing on the serpent and a body spanning eight valleys and eight ridges. That is closer to a living mountain range than to an animal. Other Japanese serpent-slaying tales, from Koga Saburo at Suwa to the Yahiko serpent of Echigo and the Aso traditions around Takeiwatatsu, can be read in the same serpent-deity line. The Kojiki's account of Omononushi in the reign of Sujin, where a god appears as a snake, forms another great pole of ancient Japanese serpent worship. Sand iron and the bloody riverbed. Oku-Izumo was a center of sand iron and tatara smelting. Kanna-nagashi washed mountain soil through channels, separating sand iron and staining riverbeds with red earth and iron. The Kojiki's image of Orochi's belly as always bloody and raw can therefore be read as the mythic language of a red river. Furnace fire, the relative independence of ironworking groups, and the seizure of good blades by central power all make the ironmaking reading persuasive. Mizu no Bunka issue 54 presents this as one of the key local theories. The repeated eight. Yamata, eight heads and eight tails, eight valleys and eight ridges, yashiori sake, eight vats, and the "Yakumo tatsu" poem all make eight the story's organizing number. It may mean literal eight, sacred multiplicity, or both. The eightfold fence around Kushinada-hime gives the number a ritual and spatial force. Even the placement of the tale in book one, section eight of the Nihon Shoki has invited speculation, though that remains an inference about editorial intent. Izumo drawn into Yamato myth. Orochi's defeat can also be read politically. A serpent deity of Izumo is slain by Susanoo from the Takamagahara sphere, and the treasure inside its tail enters the imperial regalia. The later kuni-yuzuri myth of Okuninushi follows the same broad problem: how Izumo is brought into the central mythic order. The Izumo no Kuni no Miyatsuko lineage claims descent in the Susanoo line while serving Okuninushi's cult, so the story survives both as a myth of conquest and as Izumo's own ritual memory. Iwami Kagura keeps the serpent moving. Iwami Kagura's Orochi turns the ancient myth into a present-day bodily performance. Paper-and-bamboo serpent bodies coil and strike across the stage, and several serpents may fight at once. Once an offering at shrine festivals, the performance also became a postwar attraction and regional symbol. What the audience sees is not an abstract myth, but the way Izumo and Iwami continue to tell the serpent story through movement, sound, and spectacle.

An elderly woman with white hair and a body hardened by life in the mountains, she is famed as the nurturing figure who raised Kintaro. Her deeply lined face reflects priceless life experience, and she offers precise guidance to the lost. Though she may appear strict, a profound love resides beneath the stern exterior.

Deep in the Ashigara Mountains, in a secluded hollow along bamboo ridgelines untrodden by humans, dwells a lineage of yama-uba known as the Yae-giri Mother Form. Bathed at birth in dew gathered on layered paulownia leaves and nourished by the breath of the mountains, this line is said to conceive children through union in dreams with an akairyū—an “red dragon” that appears on nights when crimson vapors gather. They rarely mingle with the human world, opening paths for those who keep the mountain’s order and baring fangs at those who trample its law. The Ashigara Yae-giri Mother Form takes as her charge the raising of children, favoring those with especially strong vital spirit. With few words she teaches how to split firewood, read the presence of beasts, ford streams, follow the courses of stars, and use the virtues of roots, leaves, and bark. When a child stumbles on a stone she watches and smiles, and when blood is drawn she silently applies moss juice. It is not pampering but passing on the mountain’s severity as it is. The crimson vapor seen in the Konjaku Monogatari is her warding veil, a barrier that blinds the eyes of outside gods. When Yorimitsu ascended from Kazusa, he recognized that vapor and sent Watanabe no Tsuna, an act born of the ancients’ intuition about this Mother Form’s power. In a thatched hut lived an old woman and a youth not yet twenty. The old woman called herself a demon-woman and felt no shame for her bond with the dream-red dragon, saying only that the child was born according to the mountain’s law. The boy she raised was later named Sakata Kintoki and became famed, yet once a child enters the world the Yae-giri Mother Form releases attachment and fades like mountain mist, caring nothing for wealth or honor, wishing only that the mountain’s balance remain unbroken. In Edo times, when the Kimpira jōruri was popular, she was portrayed as an ogress, but in old tales of Ashigara, oni signifies awe-inspiring power and is not confined to evil. Stories of bearing a thunder child and of a red dragon entrusting a child to the paulownia atop Mount Kintoki show this lineage’s dual nature of receiving from heaven and nurturing on earth. When sharing the mountain’s bounty she wears the face of an old mother, against ravagers she takes the aspect of a peak-dwelling oni. At midnight, when crimson vapor drapes the ridge, she consults the stars over a child’s fate and, if needed, commands beasts and trees to open the way. She leaves no treasure, only marks carved in wood grain and the remembered weight of a hand-axe in a child’s palm. Even now, on mist-laden mornings deep beyond the Ashigara Pass, she is said to listen for the breath of those who are meant to be raised, hidden within the rustle of bamboo wrens.

While the *Yamawaro* is a mountain monster unique to the mountainous regions of Kyushu, its greatest originality lies in the fact that it forms two aspects of a single body with the *kappa*. The fact that Terajima Ryoan noted the habitation of *Yamawaro* in Chikuzen and Goto in *Wakan Sansai Zue* is evidence that early modern intellectuals incorporated the folklore of grotesque beings from the western mountains into the framework of natural history, showing that the Goto Islands were designated early on as a land of *Yamawaro* traditions. In the migration belief, it is said that the *kappa* of the river and the *Yamawaro* of the mountain switch places at the boundary of the spring and autumn equinoxes, which is thought to be a crystallization of the agricultural calendar, water god worship, and mountain god worship into a single existential image. Its assistance to woodcutters and the reward of rice balls, its love of sumo, its dietary preference for salt and crabs, and its grotesque form with dog ears, red hair, and a single eye are all supported by the *Wakan Sansai Zue* and the oral traditions of various parts of Kyushu. Amidst life in the Goto Islands, surrounded by sea and mountains, the *Yamawaro* has become inextricably linked to the *kappa* (*gataro*), becoming an entity that embodies the local spirituality penetrating both the waterside and the mountains.

This version looks at the yamawaro — the kappa's "other half" — from the side of life in the mountains. If the kappa is the being that menaces people at the water's edge, the yamawaro is the one that appears at the worksites of mountain labor. It helps woodcutters and charcoal burners haul their timber, taking sake or rice balls in return. Yet the exchange follows a strict code: hand over the promised goods first and it runs off without working, and break a promise and it flies into a furious rage and brings down misfortune. To those who worked the mountains, the yamawaro was at once a dependable partner and a neighbor not to be trusted, one that bared its fangs at any lapse of courtesy. The tales of the yamawaro are packed tight with the eeriness of the mountains: the "tengu-fell," the sound of a great tree crashing down when no one is there; a voice that mimics human songs and the strokes of an axe to the life; and the strange weakness of disliking the line of a carpenter's ink pot. These are the very dread felt by those who venture deep into the hills. And the legend of the "crossing of the kappa" — entering the mountains at the autumn equinox and returning to the rivers at the spring equinox — ties the yamawaro and the kappa together with a single thread. A single water god that passes between mountain and river — its mountain face is the yamawaro.

Yao-bikuni is recorded in a 1449 diary as a long-lived nun who came from Wakasa to Kyoto; in the early modern period, she became linked to a story of a girl who ate mermaid flesh. More than two hundred years old in *Yasuyoshi-ki*, eight hundred years old in *Gaun Nikkenroku*, and more than four hundred years old in *Honchō Jinja Kō*, the shifting numbers trace the legend’s long development.

A type of tsukumogami typical of early modern yokai art. The hair-spear used both as a practical weapon and as a symbol in processions was thought to accrue spiritual potency through associations with masters and tales of valor. In Hyakki Tsurezure Bukuro, Sekien depicted it wielding a wooden mallet, assigning it a specific object-name while drawing on older iconographic bones. The name Yarigechō likely arose where Night Parade motifs from the Muromachi era, Edo antiquarian taste, and the culture of famed implements converged. Modern print editions and nishiki-e varied the image, sometimes stressing the spear’s decorative plumes, yet it lacks distinctive oral lore and is known mainly through pictures and bibliographic notes.

The Yokkabu-i ritual is a rare folkloric example that beautifully blends water god worship with the discipline of children in the Satsuma Peninsula, where Garappa (kappa) legends remain strong. The method of manifesting an extraordinary "god" using eerie masks made of palm bark and everyday tools like the *yogi* conveys the ancient layers of Japan's masked deity and visiting deity faiths. While the continuation of such traditional events is threatened by a declining and aging population, it has functioned as a crucial cultural mechanism to deepen community bonds and pass down both the terrors and blessings of nature to the next generation.

The Position of Grotesque Deities in Kiki Mythology. While the basic description touches on the accounts in the *Kojiki* and *Nihon Shoki*, the deep dive explores Yomotsushikome's position as a "grotesque deity" within the mythological system. Deities in *Kiki* mythology are broadly classified into three layers: (1) Takamagahara lineage (heavenly/pure deities), (2) Ashihara-no-Nakatsukuni lineage (earthly/indigenous deities), and (3) Yomi lineage (deities of the dead/grotesque deities). Yomotsushikome belongs to the third lineage, forming a cohesive system alongside Izanami (the goddess stationed in Yomi), the Eight Thunder Deities, and the Underworld Army. *Kiki* mythology is not a simple dualism of good and evil; it possesses a three-tiered structure of "life, purity, and light" versus "death, impurity, and darkness," where grotesque deities are positioned as essential entities upholding the order of the underworld. Etymology of "Shiko"—The Semantic Field of Ancient Japanese. Interpreting "shiko" as "ugly" is a reductive interpretation from the Middle Ages onwards. In ancient Japanese, "shiko" was a rich word connoting "strength, hardness, and terror." Cognate words like "shikobuchi" (rocky abyss) and "shikofune" (sturdy boat) express the hardness of coastal rocks. "Shikome" was not merely an "ugly woman" but understood as a "hard, strong, and terrifying female demon-deity." The names of ancient deities tended to be based on "spiritual power and function" rather than "visual features," positioning Yomotsushikome as a "female demon-deity with terrifying power governing death." The fixed image of a "flesh-rotting, fanged hideous hag" in medieval picture storytelling is a later reconstruction distinct from her original mythological figure. East Asian Comparison of Peach Warding Beliefs. The episode of Izanagi using peaches to repel Yomotsushikome serves as a key subject in comparative religion regarding East Asian warding culture. In Chinese Taoism, warding off evil spirits using peach wood swords, peach charms, peach seals, and peach offerings was systematized and widely spread to East Asian regions. The magical power of the peach repeatedly used in Japanese court rituals (Tsuina, Tango no Sekku, Momo no Sekku) was formed through the complex intertwining of the Izanagi myth in the *Kojiki* and Chinese Taoist peach worship. This is a classic example of how ancient Japan constructed its unique system while assimilating the religious cultures of the Chinese mainland and the Korean peninsula. The Pursuit Tale as a Narrative Type. A hero escaping from the land of the dead by throwing magical items that transform to delay pursuers—this is known in world mythology as the "Magic Flight" motif, a widely distributed narrative type. Similar tales exist in the Greek myth of Orpheus and Eurydice, Eastern European folklore of Baba Yaga, and Native American creation myths, demonstrating a universal structure of ancient human concepts of the underworld and escape narratives. The tale of Izanagi and Yomotsushikome holds exceptionally high comparative mythological value as one of the oldest literary records of this global narrative type in East Asia. The Geography of Yomotsu Hirasaka—Relationship with the Izumo Belief Sphere. The modern estimated site of Yomotsu Hirasaka in Higashi-Izumo-cho Iya, Matsue City, Shimane Prefecture, is located in the core region of the ancient Izumo belief sphere, alongside the Izumo Kuni-no-Miyatsuko stronghold, Kumano Taisha, and Kamiarizuki legends. In the *Kojiki* and *Nihon Shoki*, Izumo is depicted as the intersection of the three mythological layers—Takamagahara, Ashihara-no-Nakatsukuni, and Yomi—and placing the "entrance to Yomi" in Izumo was no coincidence. It reflects Izumo's status as the religious center for "death, the otherworld, and Ne-no-Katasukuni" in ancient Japan. Myths involving Okuninushi, Susanoo, Izanagi, and Izanami intersect in this region, serving as the key to deciphering ancient religious geography. Reduction Since the Middle Ages and Modern Renewed Interest. In medieval sermons, picture storytelling, Noh, and Joruri theater, Yomotsushikome was fixed into the image of a "flesh-rotting, fanged hideous hag," losing the original ancient semantic field of a "strong female demon-deity." However, since the 2010s, amidst a renewed interest in Japanese mythology, re-evaluations based on findings in ancient linguistics, mythology, and archaeology are progressing. Modern subcultures such as the *Megami Tensei* game series, *Record of Ragnarok* manga, and *Demon Slayer* anime functionally reconstruct ancient mythological materials, thereby reintroducing the mythological worlds of Yomotsushikome, the Underworld Army, and Yomi to younger generations. This is a symbolic example of cultural historical circulation from ancient to modern times. Positioning as "Japan's Oldest Yokai". Yomotsushikome is a female demon-deity appearing in the *Kojiki* (712 CE), Japan's oldest extant book, giving her a unique status not just as a "post-Heian yokai" but as a "grotesque deity recorded in the original texts of Japanese mythology." Predating the yokai systems involving oni, tengu, and kappa that formed from the Middle Ages onwards—in an era where the boundary between ancient gods (kami) and yokai was still undifferentiated—she is a core subject for tracing the origins of yokai studies. Dismantling the binary opposition of "is it a god or a yokai?", she serves as an excellent starting point for examining the rich, multi-layered nature of ancient Japan's grotesque deities.

Yonatama is a sea spirit of the Miyako Islands, described either as a mermaid or as a fish able to speak in a human voice. Fishers on Shimojishima caught one and tried to roast it over their net. When a voice from offshore called its name that night, Yonatama answered that it was trapped in the fire and asked its companions to send a tsunami to save it. Only a mother and child are said to have escaped to Irabujima in time. After the wave, the ground beneath the fishers' house collapsed, and the hollow was remembered as the origin of Tōriike. The name Yonatama is commonly read as a union of 'sea' and 'spirit,' and the being embodies both the sea's bounty and its anger. Interwoven with memories of the Great Meiwa Tsunami of 1771, the tale remains a warning against treating the ocean with contempt.

Yuki-onna is a broad name for female apparitions that appear on snowy nights and mountain roads. An early use of the word appears in the 1642 *Takatsukuba*, and regional traditions include a harmless snow spirit who makes bridges, a woman who leaves bloody footprints, and a figure invoked in child-minding words. The familiar image of white breath, Oyuki as a wife, and a broken secret became widely known through Lafcadio Hearn’s *Kwaidan* (1904).

Based on the Snow Child figure from Echigo Province. It appears as a small child on snowy days, visiting from the doorway on blizzard nights to warm itself by the hearth. When cared for, it comforts the household and may help with chores, yet with the first signs of spring it loses strength and fades. It shows no malice and instead bears the character of a guest deity, a seasonal visitor heralding winter’s presence. Its visits recur but never last, and finally cease, reflecting the impermanence of snow. It is also called “Yuki-warashi” or “Yukiko,” names that all link snow with a childlike form.

The *Yukijoro* is a highly unique snow woman nurtured by Yamagata, one of Japan's premier heavy snowfall regions. While snow women nationwide are told of as cruel monsters who freeze travelers to death, Yamagata's *Yukijoro* strongly retains "gratitude-type" tales where she rewards human compassion with blessings. In the Oguni region, her true identity is said to be a princess who descended from the moon world with the snow, losing her way back and appearing on nights lit by the snow's glow—a rare archetype blending East Asian moon worship with the snow woman. In folktales, a house that coldly rejects the white-robed woman begging for lodging falls into ruin, while a house that welcomes her warmly is left with the blessing of a lump of gold. The *Yukijoro*'s body melts upon touching human warmth, leaving grace in the wake of her melting. Furthermore, in the Mogami region, there are tales of an *Ubume*-like snow woman trying to hand over a child, or a snow woman leading a cow, showing that the *Yukijoro* does not fit into a single mold. The terror of the freezing winter, and the emotion of a snow country where one cannot survive without nevertheless cherishing the snow, are superimposed on this multifaceted snow woman.

An image based on the “Yūrei” in Toriyama Sekien’s Gazu Hyakki Yagyō, published around 1776 (An’ei 5). In a nighttime graveyard a woman’s ghost appears between drooping willows, wearing a white burial robe and a forehead cap, raising her arms as if to halt a passerby. It is a transitional depiction from before footless forms and the triangular headcloth became fixed conventions, emphasizing the lifelike force of the arms and the willow and gravestones as symbols of place. Sekien’s plates organized contemporary strange tales, Buddhist views, and funeral customs, profoundly shaping the visual codification of yūrei. While indicating gender and costume, the image leaves the source of attachment unspecified, inviting the viewer to imagine the relationship.

This form draws on the Nosoko story in which a fisher finds Zan in his net. The mermaid-like creature weeps and begs for its life. When the fisher releases it, Zan answers that mercy with a warning of an approaching tsunami, allowing the villagers who believe it to escape to the mountains. Zan is generally understood as a folkloric image of the dugong. Dugongs were long regarded in Ryukyuan waters as messengers of the gods: familiar animals of the shallows, yet beings approached with awe. Zan does not cause the disaster it predicts. It senses danger before human beings can and stands between sea and land to preserve life. Yonatama, another island spirit associated with a tsunami warning, brings the wave in anger after being roasted. Zan takes the opposite role. Together they reveal two moral faces of the sea: cruelty toward a marine creature may call forth vengeance, while mercy may be repaid with rescue. Zan remains one of the Ryukyuan sea's gentlest prophets because its power rests not on punishment, but on gratitude.

The zashiki-warashi is not simply a young god of good fortune in red clothing. Tales 17 and 18 of Tales of Tōno include a boy of about twelve or thirteen, an unseen presence known only by rustling paper and snuffling, and two young girls who leave a household. The stories associate it with a home’s prosperity or decline, but the original does not say that the children caused the disaster. As Kizen Sasaki’s 1920 collection shows, its names, forms, rooms of appearance, and explanations of origin vary greatly by region.

Based on examples by Toriyama Sekien, this image depicts an aged tea kettle manifesting with spiritual authority. Its posture and arrangement inherit compositional methods akin to the Night Parade of One Hundred Demons scrolls, often shown marching alongside Torakakushi and Yarinaga. The name plays on the kinship between chanoyu and Zen, hinting at a caricature of a Buddhist priest. By the logic of mononari, tools long used or neglected accrue ki, appear before people, and inspire awe. Meiji painters continued this iconographic lineage, and yokai catalogues and dictionaries classify it as a type of tsukumogami, though specific local legends are scant. Later commentaries add anecdotes of startling humans, but early records offer little confirmation, so it is understood chiefly through its iconographic tradition.

Shoki, a demon-quelling deity spread across East Asia from Tang dynasty lore, took root in Japan as a talismanic power against calamity and smallpox. He is depicted as a bearded martial figure in official robes and cap, glaring with fierce eyes and wielding a sword in one or both hands. He often appears hunting, trampling, or bagging small demons. At New Year and Boys’ Festival he is displayed on hanging scrolls, banners, and screens, and many townhouses placed ceramic Shoki figures on eaves or roof corners. In Japan the earliest examples trace back to late Heian apotropaic paintings; from the Muromachi period the theme became established, and by late Edo he also appeared as May Festival dolls. Images and figures were hung at entrances, gates, or the upper seat of reception rooms to stop plague deities and malign spirits. Although dedicated shrines are limited today, regional folk belief since early modern times continues, and rooftop Shoki statues are still found from Kinki through the Chubu region. His powers are symbolized by the subduing glare and swordplay that drive off evil sprites, functioning as amulets against drug harm and epidemics.

This traditional image is constructed centering around the "Ōmagatoki" entry in Toriyama Sekien's *Konjaku Gazu Zoku Hyakki* (Illustrated Hundred Demons from the Present and Past, Continued), published in the 8th year of An'ei (1779). Ōmagatoki is not a single yōkai, but the temporal condition under which yōkai begin to appear. Therefore, rather than endowing it with a personality and having it attack people, it is treated as the twilight itself—when brightness is lost and the identities of familiar landscapes and people suddenly become uncertain. Though brief, Sekien's explanation seamlessly links the definition, the uncanny, and a taboo. He first defines the time: "It means twilight. It is the time when the hundred specters arise," and immediately follows with the consequence: "In the world, it is forbidden to let children go outside." The practical warning to bring children home because it is evening and the supernatural explanation that the hundred specters arise form a mutually reinforcing structure. However, this is an explanation of "worldly custom" recorded by Sekien in the late 18th century, and it cannot be definitively said that this exact same prohibition was observed in homes nationwide since ancient times. In the lower half of the picture, a quiet, unpeopled row of houses and a pagoda resembling a temple stand still, while a large sun is setting on the far left. In the upper half, faces with horns, beast-like faces, and faces that cannot be firmly identified as human or demon peer out one after another from a cloud-like mass. The "hundred specters" (*hyakumi*) do not appear as a roster tallying exactly one hundred entities, but rather as a collective term for numerous uncanny beings whose names and forms remain unfixed. Sekien does not place a single monster in the center; instead, he transforms the entire boundary between the sky and the town into a scene of yōkai manifestation. The latter half of the text brings up the variant spelling "Hour of Wang Mang" (王莽時). In a theory recorded by Hayashi Razan before Sekien, the day corresponds to the Former Han, the night to the Later Han, and the twilight between them to Wang Mang's Xin dynasty. Sekien retold this older theory, overlaying the historical transition—where Wang Mang usurped the Former Han but his dynasty ended briefly before shifting to the Later Han—onto the boundary between day and night. This does not mean that Wang Mang himself appears as a yōkai; rather, it is an intellectual analogy decoding the sound *ōmagatoki* through the boundary of dynasties in Chinese history. The fact that dictionaries list Ōmagatoki alongside Ōmagatoki (Hour of Great Calamity), Ōmaji (Hour of the Great Demon), and Ōmōji (Hour of Wang Mang) also indicates that this word has been enveloped in multiple associations: disaster, encounters with demons, and historical intervals. The terror of Ōmagatoki lies not in the darkness itself, but in the fact that one can still see, yet cannot identify correctly. In complete night, one would prepare a lantern; but at twilight, the sensation of day lingers, and a silhouette thought to be an acquaintance might actually be a stranger. In "Kawataredoki," Yanagita Kunio surmised that in an era when it was difficult to distinguish a person from the outline of their clothing, people probably could not confirm an individual's identity until they heard footsteps and exchanged greetings. The phrases *taso kare* ("Who goes there?") and *kare wa tare* ("Who is that?") crystallize this uncertainty directly into a question. In the regional examples Yanagita compiled in *Yōkai Dangi*, voice serves to gauge the boundary between human and non-human. In Saga, a single "Moshi" (Hello) invites suspicion of being a fox; in Okinawa, one does not reply until called three times. The *Game* of Kaga, the river otter of Noto, and the tanuki of Mino and Tosa, even when disguised as humans, cannot correctly pronounce the local dialect, and their true identities are exposed through discrepancies in their responses. However, as Hirota Ryūhei cautions, Yanagita did not clearly indicate the sources for these individual examples, and one cannot conclude that they were all identical Ōmagatoki customs. Here, they are positioned as Yanagita's comparative interpretation linking twilight and the stranger. There is no fixed value on a modern clock for this hour. Even under the variable hour system of the Edo period, dawn and dusk served as the demarcations between day and night, and their positions shifted with the seasons. The time and duration of twilight differ between summer and winter, north and south, mountains and plains. Charts converting the Hour of the Rooster (kure-mutsu) to exactly 18:00 or 17:00–19:00 today are merely approximations; the essence of Ōmagatoki is not a number on a clock, but the brief transition where daytime visibility and social security begin to unravel. Therefore, one cannot "defeat" Ōmagatoki. Behaviors such as returning home before sunset, exchanging greetings with companions, and identifying others with a lantern are not magic to erase time, but practical wisdom to reduce uncertainty. When the sun sets and complete night falls, even if the world of the hundred specters continues, Ōmagatoki as the "gap between day and night" comes to an end. The core connecting Sekien's hundred specters, Yanagita's stranger, and the modern fictional use of the hour as a signal for monsters to appear lies in that single point: the unsettling wavering of classification at the boundary where things can be seen but not easily defined.