Main Reference: Tama River Folktales by Sakuhira Ishii, Arimine Shoten Publishing, 1976
Alternate sources: http://www.47news.jp/CI/200812/CI-20081205-00182.html
There used to be many kappa around Izumi Tamagawa in Komae. But they were wiped out because humans caught them to use in exhibitions and sell at markets. However despite the kappa’s extinction, the exhibitions did not end. People filled large tubs with water and put wooden dolls in them to trick customers. But long ago, the kappa were brought to Edo (Tokyo) and mistreated by the exhibition owners like in the story below.
One day, a kappa named Kusuke left his happy home in the Tama river to steal some cucumbers in a nearby field. While enjoying a pile of cucumbers, the farmer found him and sold him to an exhibition. The exhibition owner had a whip and forced Kusuke to perform all kinds of tricks for customers. One day the owner decided to make Kusuke jump through a flaming hoop.
Many customers came to see the trick. But Kusuke was afraid and couldn’t get his legs to move. The crowd jeered at him and the owner yelled and cracked his whip. Only a little girl in the audience felt sorry for Kusuke and she prayed that Kusuke could be returned to his family in the river.
Kusuke couldn’t hear the girl, and he was feeling desperate. So he took a flying leap towards the hoop. But as he leapt into the air, Kusuke began to float upward towards the ceiling and disappeared. The crowd was left in a stunned silence.
When Kusuke came to his senses, he was staring up at a blue sky and found himself caught on the branch of a large tree at Gyokusen Temple. Some children playing below heard his cries and ran to fetch the monk. The monk was not sure how the kappa got in the tree, but helped Kusuke down.
After hearing Kusuke’s story, the monk warned him not to touch things that humans were involved in and placed a talisman on Kusuke’s shell. Kusuke cried tears of gratitude.
Later, when kappa hunters came to Tama River to catch kappa, Kusuke’s shell radiated light like a halo and the hunters collapsed from the brightness. Thanks to the talisman, Kusuke survived so long, he was the last kappa of Tama River.
They say that if you go to Gyokusen Temple even today, you can see the outline of a kappa on the branch where Kusuke landed.
(Gyokusen Temple is a 2-minute walk from Izumi Tamagawa Station. The kappa image is on the large tree on the left side of the inner mountain gate.)
I went to Gyokusen Temple (it is on my way to work), but I could not find said tree. 🙁