Nobusuma

Lore & Background

The nobusuma is said to latch onto a human from behind and cover his eyes and mouth, perhaps to suck blood. It also attacks animals to feed on their blood, according to other sources, and is said to consume fruits or tree-nuts. One source explains that after chomping the tip off a lit torch, it engages in fire-eating and -breathing behavior. The yamachichi is a separate yōkai with its own distinct lore, and the transmutation chain linking it to the nobusuma is not standard in most folklore sources.

Reader's Guide

The nobusuma represents a fluid category of yōkai that blurs the line between natural animal and supernatural monster. Its lore, localized in Edo, draws on observations of flying squirrels and bats, whose nocturnal gliding and torch-blinding behavior may have been misinterpreted as yōkai attacks. The creature's depiction in illustrated books by Sekien, Shunsen, and Kuniyoshi shows its enduring presence in Edo-period art and literature. The nobusuma also connects to other yōkai like momonjī and yamachichi, illustrating how Japanese folklore often links aging animals to monstrous transformations. Its inclusion in encyclopedias like Wakan Sansai Zue and references to Chinese sources (Bencao Gangmu) show cross-cultural influences. The nobusuma's legacy lies in its role as a cautionary figure in mountain folklore and as a subject of artistic and scholarly interest, reflecting how natural history and folk belief intertwine.

Did You Know?

• The name nobusuma translates to 'field bedding', possibly derived from fusu mo (伏す裳; 'lying-down/sleeping gown').
• The nobusuma is also called tobikura (飛倉; 'flying warehouse') and was said to cover over the face of humans.
• Utagawa Kuniyoshi depicted swordsman Miyamoto Musashi fighting a giant bat-like creature, but the print does not specifically identify it as a nobusuma.

Identity & the Transmutation Question

The nobusuma occupies a fascinating liminal space in Japanese yōkai taxonomy, as its true nature has never been settled. Some lore identifies it as a transmuted bat, while other traditions root it firmly in the world of flying squirrels—specifically the giant musasabi or the smaller momonga. Toriyama Sekien's 1779 Konjaku Gazu Zoku Hyakki illustrates the creature with the body of a flying squirrel, though his accompanying text notes bat-like features including fur and fleshy wings. Kikuoka Senryō's earlier 1734 commentary takes a more restrained view, describing only the folded fleshy wing as resembling a bat's, without claiming the whole creature is bat-shaped. A third, more dramatic theory proposes a full transmutation cycle: an ordinary bat ages into a nobusuma, which in turn matures into the yamachichi, a vampire-like entity that drains the breath from sleeping humans. This progression from harmless mammal to deadly predator gives the nobusuma a unique place as a mid-stage in a monstrous life cycle, rather than a fixed species.

Predatory Behavior & the Torch Ritual

The nobusuma's predatory behavior, as recorded across multiple Edo-period sources, paints a creature of unsettling versatility. In its most terrifying guise, it swoops down onto a human traveler, latching its forepaws over the victim's eyes and mouth in a blindfolding, gagging grip, then proceeding to drain blood from the person on a mountain path. Other accounts describe it attacking animals to feed on their blood, while still others portray a far gentler diet of fruits and tree-nuts. The most bizarre behavior involves fire: the creature is said to bite the tip off a lit torch carried by a night traveler, extinguishing the flame, and then engage in a kind of fire-eating and fire-breathing display with the smoldering piece. This torch-snatching habit made it a particular dread of those traveling after dark. The related yamachichi, its supposed elder form, operates with even deadlier intent, sucking the very breath from a sleeping person—a deed that proves fatal if no one witnesses it, yet paradoxically extends the victim's life if another human happens to see the act.

Etymology & Cross-Cultural Lineage

The name nobusuma, written with the kanji 野衾, literally translates to "field bedding," a term that evokes the image of a sleeping garment spread across open ground. The word fusuma here is glossed as a kakebuton, the top cover of a futon, or a "night robe," and is thought to derive from the older phrase fusu mo, meaning a "lying-down gown" or sleeping garment. This etymology suggests the creature was originally conceived as something that drapes over a sleeper, reinforcing its association with nocturnal attacks on the vulnerable. The creature's regional naming is equally varied: the 1712 encyclopedia Wakan Sansai Zue records that nobusuma is the colloquial term, while the Kantō region calls it momoka and the western provinces use itaojiki. The Wakan Sansai Zue entry itself is derivative of the Chinese compendium Bencao Gangmu (1596), which describes the leishu flying squirrel as consuming smoke rising from fire—a detail that echoes directly in the nobusuma's legendary fire-eating behavior. This cross-cultural lineage shows how a real mammal's observed habits were absorbed into Japanese supernatural lore through Chinese naturalist texts.

Iconography & the 1798 Edo Sighting

The nobusuma has left a distinctive mark on Japanese visual art across more than a century of ukiyo-e production. Toriyama Sekien's 1779 Konjaku Gazu Zoku Hyakki presents the creature as a fur-covered, winged flying squirrel, establishing the visual template that later artists would follow or modify. Takehara Shunsen's illustration in the 1841 Ehon Hyaku Monogatari continues this tradition, depicting the bat-type variant within the transmutation narrative. By 1853, Ryōsai Kanjin Masajumi painted the tobikura in the act of covering a human's face in the Kyōka Hyaku Monogatari, capturing the creature's most iconic predatory pose. Perhaps the most surprising appearance belongs to Utagawa Kuniyoshi, who included a bat-like nobusuma in his Musashi series (c. 1826–27), showing the legendary swordsman Miyamoto Musashi slaying the creature in the mountains—a scenario with no historical basis beyond Musashi's well-documented travels across the country. A 1798 incident recorded in the Baiō zuihitsu collection adds a quasi-empirical note: a weasel-like winged beast that attacked cats in Edo was captured and identified as a nobusuma from the deep mountains, its wings described as present but not fully formed.