In the Iwami region of Shimane, Nure-onna appears on the shore, hands her baby to a passerby, and returns to the sea. Ushi-oni then emerges to attack. Once accepted, the child becomes a heavy stone that cannot be put down, holding the victim in place until Ushi-oni devours them. An Ōda story says that a cornered Ushi-oni cried, 'What a pity,' in the same voice as Nure-onna, supporting the idea that the two were one being.

No known primary source, however, directly joins the serpent-bodied woman of the picture scrolls to Iwami oral tradition. The image and the story may have traveled along separate paths. Fujisawa Morihiko's Yōkai Gadan Zenshū: Nihon-hen^[4] mentions a Nure-onna tale from Echigo in the Bunkyū era, but does not identify its original source. The familiar modern figure was therefore shaped in part by later researchers gathering scattered accounts.

Wet hair, a serpent's body, and the child used to immobilize a traveler also overlap with Iso-onna on the Kyūshū coast and Nure-onago traditions in Shikoku and the Chūgoku region^[3]. Nure-onna is best understood as one form within a wider family of female waterside apparitions rooted in coastal life, women divers, and the hazards of the shore. Her sudden arrival from the sea and the binding act of accepting a child turn the uncertain boundary between land and water into a lasting tale of danger.