There is a large waterfall called Lung-men in China. It scales ten jyō (approximately 30 meters) high, and the speed at which the water falls is quicker than that of an arrow shot down from above by a strong warrior. Here, large schools of funa (carp) gather and attempt to climb the waterfall. If a funa is able to climb to the top of this waterfall, it would be transformed into a dragon. However, not one in a hundred, or a thousand, or ten thousand, or even one in ten or twenty years is able to climb to the top.

They are often drifted off along the way by the rapids, or preyed upon by eagles, hawks, kites, and owls. If not, they are caught by fishermen lined up on both banks, left and right, over a range of ten chō (about 1090 meters). They lay nets, use buckets, and some use spears to catch the funa. These conditions make it almost impossible for a funa to become a dragon. The road to becoming a Buddha is not any simpler than a funa climbing Lung-men or someone of lowly status gaining membership into the court.

Ueno-dono Gohenji, A Reply to Lord Ueno, Writings of Nichiren Shōnin, Faith and Practice, Volume 4, Page 162-163