According to legend, a bodhisattva turned into a fish and swam among rice fields, mountain streams and rivers to help people get rid of pests and protect one side of the water and soil. It is said that one day, an old man was walking on the river bank and accidentally fell into the water. Because of his age, he couldn't swim on the river bank and fluctuated in the water. At this time, snakes, mice and river monsters all came to hurt him. When the Bodhisattva found out, she came to rescue him. Swarms of bodhisattva fish came to fight the snake, rat and river monster, picked up the old man and sent him to the river bank. The old man is safe and sound, but many bodhisattva fish have become food in the mouths of snakes, rats and river monsters. Since then, the story of this bodhisattva who gave his life to save lives has been widely circulated among the people. Every time I see Bodhisattva fish in the mountains and streams in Tanaka, I know that the water and soil in this area are sheltered by Bodhisattva. Later, more people kept bodhisattva fish at home to ward off evil spirits.