Nure onago appear as disheveled-looking young girls with matted, wet hair. As the name implies, they are soaked with water from head to toe. Often they are covered with dead leaves and things which have stuck to their dripping bodies. They are often encountered on roads near swamps, rivers, and coasts, or during nights of heavy rain, wandering about, dripping and sopping wet.
Travelers along the coasts and rivers of Shikoku and Kyushu occasionally encounter these (apparent) young girls, lost, and soaked to the bone with water. Most people who witness such a pathetic sight rush over quickly to help the poor lost girl. When a human draws close to a nure onago, she looks up into their eyes and smiles. If the smile is returned, she will follow the helpful stranger human, sticking by him forever, wherever he goes, always dripping and stinking of mildew and swamp water. Although she causes no particular harm, her constant presence is often enough to ruin the rest of a person’s life.
Ignoring a nure onago and refusing to return her smile before attracting her attention is the only way to avoid this yokai. Unfortunately by the time her true nature is discovered, it is often too late.
Nure onago come from the strong feelings of loss and sadness shared by widows of drowning victims particular those widows of sailors lost at sea. These feelings build up and materialize into a nure onago, whose desire for attention is the amplified desire of heartbroken widows to see their husbands again.
Nure onago have very similar behavior to hari onago, and the two are sometimes grouped together as warai onago, smiling girls. Both are also found in Shikoku, suggesting a possible relation between the two. They should not, however, be confused with the similarly named nure-onna, which is much larger and more dangerous.