On the historical event according to "Gokanjo" (History of the Later Han Dynasty), one of 24 dynastic histories of Chinese official history, a lot of fish tried to swim up a waterfall called Ryumon in the rapid stream of the Yellow River, but only carp could wax on and thus became dragons.
中国の正史、二十四史の一つである後漢書による故事で、黄河の急流にある竜門と呼ばれる滝を多くの魚が登ろうと試みたが鯉のみが登り切り、竜に成ることができた。