Oshirasama, the cult of silk or why you will never look at a silk cocoon the same again….
There was once a girl who fell in love against her parents wishes. Her father opposed her choice in this future husband. That’s because he was a horse. A real, four-legged, tail swishing horse. Nowadays we have medication, serious medication, for that sort of thing. Back then, the father felt the only thing he could do was chop the horse up and hang his skin over the branches of a nearby mulberry tree.
The poor girl finds her darling hanging there and is understandably distraught. According to the legend, she wrapped herself in his skin. (There’s medication for that now too, right?) The gods transformed them into a silk worm cocoon and that is how we got silk. Bet you didn’t know those squirmy silkworms are just incidental. This myth is told in both China and Japan but has an especially strong following in northern Japan — traditional horse country. Cringe.
At Oshirasama shrines in Tohoku, the male deity is a horse, the female, well, a girl. Worshippers pick a silk cloth and after writing their wish, wrap the figure and place it with the others.
This link has a good explanation of the cult though nothing about the legend. http://eos.kokugakuin.ac.jp/modules/xwords/entry.php?entryID=221