My Lord Bag of Rice
"My Lord Bag of Rice" (in Japanese, Tawara Tōda [俵藤太 "Rice-bag Tōda"]) is a fairy tale about a hero who kills the giant centipede Seta to help a Japanese dragon princess, and is rewarded in her underwater Ryūgū-jō 龍宮城 "dragon palace castle".
The 1711 Honchō kwaidan koji 本朝怪談故事 contains the best-known version of this Japanese myth about the warrior Fujiwara no Hidesato. There is a Shinto shrine near the Seta Bridge at Lake Biwa where people worship Tawara Tōda 俵藤太 "Rice-bag Tōda" (a pun between tawara "straw rice-bag; straw barrel" and the Japanese name Tawara 田原).
In olden times, when Fujiwara no Hidesato (who lived in the first half of the tenth century) crossed the bridge, a big serpent lay across it. The hero, however, was not at all afraid, and calmly stepped over the monster which at once disappeared into the water and returned in the shape of a beautiful woman. Two thousand years, she said, she had lived under this bridge, but never had she seen such a brave man as he. For this reason she requested him to destroy her enemy, a giant centipede, which had killed her sons and grandsons. Hidesato promised her to do so and, armed with a bow and arrows, awaited the centipede on the bridge. There came from the top of Mt. Mikami two enormous lights, as big as the light of two hundred torches. These were the centipede's eyes, and Hidesato sent three arrows in that direction, whereupon the lights were extinguished and the monster died. The dragon woman, filled with joy and gratitude, took the hero with her to the splendid Dragon-palace, where she regaled him with delicious dishes and rewarded him with a piece of silk, a sword, an armour, a temple bell and a bag (tawara) of rice. She said, that there would always be silk left as long as he lived, however much he might cut from it; and the bag of rice would never be empty.
Hidesato subsequently donated this bell to Mii-dera temple at Mount Hiei but it was stolen by a priest from rival Enryaku-ji temple. He threw it into a valley after it spoke to him, and when the cracked bell was returned to Mii-dera, a small snake (the dragon) used its tail to repair the damage. The 14th-century Taiheiki records an earlier version of this legend about Hidesato, set during the Genpei War, but instead of the dragon turning into a beautiful woman, it transforms into a "strange small man" – the Dragon King himself.
According to Azuma Kagami, he was claimed as an ancestor by Ashikaga Tadatsuna, under the name of Tawara Toda Hidesato, from 10 generations ago.