Kuchisake-onna

The most accepted origin in the provided sources places the modern legend in Gifu Prefecture, Japan, emerging in 1978 and spreading nationally in 1979 via newspapers and magazines. In modern accounts she is variously framed as the onryō (vengeful spirit) of a wronged woman and as a yōkai incorporated into contemporary catalogs of uncanny beings. Some commentators trace similar motifs to earlier (Edo-period) tales, but that suggestion is presented as interpretive rather than definitively documented in the supplied materials.

Typically described as a pale, long straight black–haired woman who hides a mouth slit from ear to ear and often covers her face with a surgical mask, handkerchief, or folding fan until revealing the mutilation. Many accounts present her as otherwise attractive and notably tall — commonly cited around 175–180 cm (5'7"–5'9"), though some tellings report much greater heights (claims up to ~244 cm appear in variants). She is frequently depicted holding a sharp implement (scissors, knife, machete, scythe or similar). Some versions add numerous sharp teeth within the slit mouth.

Her defining folkloric action is to approach potential victims and ask an appearance-related question (commonly rendered as "Watashi, kirei?" — "Am I beautiful?"). If the respondent answers "no" in many versions she kills them on the spot; if they answer "yes," she reveals her mutilated mouth and repeats the question — subsequent answers can lead either to immediate killing, nocturnal murder later that night (in some variants), or to having the respondent's mouth cut to resemble hers. Some accounts describe her possessing supernatural speed. Different tellings disagree about exact outcomes for particular responses, and survival often depends on ad-hoc conversational tricks or distractions.