Once in ancient times a long bearded, white-hairded sage covered in wrinkles descended from his pure home country of Moon to the Earth. The sage disguised himself as a hungry beggar and began asking earthlings for food to test purity of their hearts.

Firstly the disguised sage turned to a monkey and asked it to be spared from starvation and death, to be fed food per custom. Monkey swiftly climbed tree and gathered fruit for him and presented them before him. He accepted and ate.

Secondly the disguised sage turned to a fox, the fox brought him a freshly catched fish from a stream. He accepted and ate.

Thirdly the disguised sage turned to a rabbit, the rabbit only could bring him grass for his meal, the rabbit laid the grass at his feet uncertain.

Rabbit ashamed of itself; looking at the useless grass thought deeply and decided... He got the beggar to build a bonfire promising to prepare food for him. Once flames were tall - the rabbit proclaimed "Men don't eat grass. Men eat meat". The rabbit let go of the grass from its mouth, and threw itself into the flames.

Beggar pulled the rabbit from fire. For its pure action of selflessness the beggar revealed his true nature as an immortal; a sage. He took the rabbit by its ears and rapidly dashed with him back to the realm of Moon where land is pure to match the virtuous rabbit.

The rabbit lives on, on the surface of the Moon, centuries and millennias later. Processing mochi full of medicine, of lunar herbs of immortality.

I like this story a lot.