To explain Toma-Shunning Nure-Onna in detail:

Among the coastal Nure-onna of northwestern Kyushu, a variant that particularly despises the handling of reed mats and thatch is called the Toma-Shunning Nure-Onna. On windless nights she appears on the beach without leaving footprints, a young woman from the waist up with black hair slicked by brine, shell-pale skin holding the moon, and eyes that reflect the distant whitecaps offshore. Below the waist she is indistinct like sea-mist, and if trod upon there is only sand with no true form. From behind she bears a jagged, craglike shadow like a collapsed rock face, and if one’s gaze falters she seems nothing more than a shore rock. Drawn by the hush of a calm, she stares seaward; if her name is called or a careless voice is thrown at her back, she answers with a shrill cry. The scream overlaps the roar of the tide and cuts the ears, her loosened hair stretching like wet seaweed to entangle the caller. Each briny strand bites the skin like the barb of a fishhook and is said to draw up warm blood along the hair. Yet if three old thatch stems from a reed mat are placed over the chest not as a cross but in the shape of the character for river, her hair recoils from the thatch, and she cannot step on the edge of the mat, only drip seawater in frustration from the gunwale. She favors boarding boats by their stern line; if a stranger’s harbor leaves the stern line set, at midnight she will crawl up it, slip in over the rail, and drape her hair over sleepers’ faces to steal their breath. Thus old fishermen followed the rule of taking in the stern line when calling at a port, dropping only the anchor and keeping watch at the bow while reading the wind. She is susceptible to the human-made ideas of knots and naming in ropes; if the rope is cinched hard while whispering the owner’s name three times, she cannot unravel that name and cannot travel along the line. Though drawn by the grudges of the drowned, she does not harm indiscriminately. When she sees discarded reed mats or thatch, or cut ropes drifting in the tide, she scents the neglect of the hands that wove them and approaches their owner’s boat. Conversely, those who dry nets and mats without letting the ends trail into the sea or blocking the tide’s path may find her invisible presence come near and, by the creak of moorings, warn of a calm about to break, old skippers say. In parts of the Fukuoka coast, it is said she walks the water not for lack of feet, but because she avoids reed mats, stepping only on the thinnest skin of the waves. Northern Kyushu has a crab-incarnation theory, but this Nure-Onna does not hate crabs; rather, when shore crabs scuttle, she draws in her hair and returns to rock. Her name varies by place—Iso-Onna, Nure-Onna, Sea Princess—but her ties to the etiquette of thatch and rope are constant. To avoid her: do not call to a woman’s back on a night beach, do not leave a stern line fast in unfamiliar ports, and place three thatch stems in a river shape where you sleep. Keep these and she will only turn her white offshore eyes toward you, then blend into rock-shadow and unravel into the tide mist, leaving only her presence to be told as footprints that were never there by morning.