The carp is generally seen as an emblem of longevity, since it can become quite old, of wealth, abundance and perseverance, since it struggles against the river currents. The carp or koi is also Japan's major pet fish. It is called the king of river fish and has been long regarded as a 'joyful' fish. In Japan, Samurais in Muromachi Period adored the bravery Kois possess.
In the north of China the Yellow River (Huang Ho) flows across the Chinese continent. One legend says that if a carp successfully manages to swim up a valley of rapids called the Longmen Falls (Dragon's Gate) deep in the Kunlun Mountains, it can transform itself into a dragon. Because of this legend the carp has became a symbol of human's success in life.