A portrayal of the Ippon-datara based on records from Kii and Kumano through Nara. It is said to be one-eyed and one-legged, but firsthand sightings are rare; in many regions a single large track left after snowfall is taken as proof of its presence. Its most notable trait is appearing on December 20, the “Hate-no-Hatsuka,” a day overlapping taboos of mountain deities and roads, effectively discouraging entry into the mountains. In its link to smithing, folklore explains the one-leg one-eye form as derived from the tatara blower treading the bellows with one foot and watching the furnace with one eye. In the Obagatōge lineage it is equated with the oni-god Inosasao, once a terror of the peak but sealed by a monk and released only once a year. In Kumano and Itsukushima it is said “only footprints appear, not the body,” feared yet seldom directly harmful. While stories of one-legged snow spirits (such as Yuki-nyūdō and Yukibō) have blended with it, this entry centers on the Kumano–Nara stream, emphasizing three points: the taboo day, the single track, and the blacksmith-origin theory.
Character Profile
This section is our own creative profile for storytelling. It is not historical fact or scholarship.
Yokai Type - Traditional Yokai
Category - Mountain & Wilderness Spirits
Rarity - Epic
Personality - avoids people, shuns those who approach on taboo days
Compatibility - less likely to clash with those who observe mountain work and hunting etiquette
Abilities - leaves a large single footprint on snow after snowfallconfuses and repels people in the mountains on taboo daysshows only its presence on night roads to make travelers turn back
Weaknesses - observance of taboo days and protective boundaries, prayers and talismans at shrines, retreats before fire and loud sounds in some locales
Habitat - mountain ranges of the Kii Peninsula including Kumano and the Kumanogōe Range, around Obagatōge in Nara Prefecture, Aki Province and the Itsukushima tradition sites