The Kappa is not properly a sea goblin, but a river goblin, and haunts the sea only in the neighborhood of river mouths.
About a mile and a half from Matsue, at the little village of Kawachi-mura, on the river called Kawachi, stands a little temple called Kawako-no-miya, or the Miya of the Kappa. (In Izumo, among the common people, the word "Kappa" is not used, but the term Kawako, or "The Child of the River.") In this little shrine is preserved a document said to have been signed by a Kappa. The story goes that in ancient times, the Kappa dwelling in the Kawachi used to seize and destroy many of the inhabitants of the village and many domestic animals. One day, however, while trying to seize a horse that had entered the river to drink, the Kappa got its head twisted in some way under the belly-band of the horse, and the terrified animal, rushing out of the water, dragged the Kappa into a field. There the owner of the horse and a number of peasants seized and bound the Kappa. All the villagers gathered to see the monster, which bowed its head to the ground, and audibly begged for mercy. The peasants desired to kill the goblin at once; but the owner of the horse, who happened to be the head man of the mura, said: "It is better to make it, swear never again to touch any person or animal belonging to Kawachi-mura." A written form of oath was prepared and read to the Kappa. It said that It could not write, but that It would sign the paper by dipping Its hand in ink, and pressing the imprint thereof at the bottom of the document. This having been agreed to and done, the Kappa was set free. From that time forward no inhabitant or animal of Kawawchi-mura was ever assaulted by the goblin.
Once there lived in the Izumo village called Mochida-no-ura a peasant who was so poor that he was afraid to have children. And each time that his wife bore him a child he cast it into the river, and pretended that it had been born dead. Sometimes it was a son, sometimes a daughter; but always the infant was thrown into the river at night. Six were murdered thus.
But, as the years passed, the peasant found himself more prosperous. He had been able to purchase land and to lay by money. And at last his wife bore him a seventh child,—a boy.
Then the man said: "Now we can support a child, and we shall need a son to aid us when we are old. And this boy is beautiful. So we will bring him up."
And the infant thrived; and each day the hard peasant wondered more at his own heart,—for each day he knew that he loved his son more.
One summer's night he walked out into his garden, carrying his child in his arms. The little one was five months old.
And the night was so beautiful, with its great moon, that the peasant cried out,—
"Aa! kon ya medzurashii e yo da!" [Ah! to-night truly a wondrously beautiful night is!]
Then the infant, looking up into his face and speaking the speech of a man, said,—
"Why, father! the LAST time you threw me away the night was just like this, and the moon looked just the same, did it not?"
And thereafter the child remained as other children of the same age, and spoke no word.
The peasant became a monk.