Hakutsuru - White Crane

The Crane Wife a Japanese folktale: Osamu was a sail maker and "as he pulled the warp and weft of his sail together, he would often think to himself, How beautiful the cranes are. Of all the birds, they are the most like sails. It is as if the wind is held in their wings." One blustery night, a large crane crashes violently into Osamu's door. The lonely sail maker nurses it back to health and watches the graceful bird soar away. This crane later returns to Osamu's door in the disguise of a beautiful young woman named Yukiko. Osamu & Yukiko fall in love, and marry, but there comes a time when there is no longer food for them to eat. Yukiko tells her husband that she can make a magic sail for him to sell in the village, but that he must promise never to look at her while she is making it. Promises are eventually broken and in the end Osamu never sees Yukiko again: "He wove simple sails for the rest of his years, there at his window, gazing at the marsh and the white cranes. And each autumn, in the season of storms, he waited for a knock on his door."

(I have also read a slight variation of this folktale called the White Crane were the crane is the daughter of an elderly couple, also the album The Crane Wife by the band The Decemberists is a retelling of this folktale.)