A woman in Shimosa province often took her stepdaughter, a girl of twelve or so, to the edge of a large pond and announced to the spirit of the pond that the girl was his to marry. She did this once when a gale was blowing and the pond was very rough. The girl was so frightened that her hair stood on end; and what with the wind and waves, and the ominous darkness of the day, she fled home again as fast as she could go with the awful feeling that something was behind her.
Dashing panic-stricken into the house, she clutched at her father and began telling him what had happened. Next, the stepmother ran in just ahead of a huge snake. The snake started at the girl, the tongue in its huge head flickering.
The father was no great lord, but he was still quick-witted. "She's my daughter," he told the snake. "This woman here is just her stepmother and she's got no right to give her away. I'm the only one who can do that and I refuse. No, a wife's bound to do as her husband says, and as far as I'm concerned she's yours, if you want her. Go ahead, take her!"
While father and daughter made their escape, the snake slithered toward the stepmother instead and coiled around her. They say she went mad and began turning into a snake herself.
The story was going around one summer ten years or so ago, which would be about 1270. Rumor had it that on a certain day that fall, both snakes would rise from the pond during a tremendous storm. There really was a storm on that day too, but I never heard whether or not the snakes appeared.