According to Japanese legend if a koi succeeded in climbing the falls at a point called Dragon Gate on the Yellow River it would be transformed into a dragon. Based on that legend, it became a symbol of worldly aspiration and advancement.
More generally, the Japanese associate koi (also known as carp) with perserverance in adversity and strength of purpose. Because of its strength and determination to overcome obstacles, it stands for courage and the ability to attain high goals.
Others say it means good fortune or luck.
The Koi Fish is symbolic in the Buddhist Religion, representing courage. Humans 'swim' through the 'ocean of suffering' without fear, just like a fish swims through water.
It is also one of the most popular and beautiful of Japanese tattoo symbols – a beauty which belives its symbolic meaning. Although Chinese in origin, the carp is now widely celebrated in Japan, particularly for its manly qualities.
In tattoo imagery, especially in combination with flowing water, it symbolizes much the same: courage, the ability to attain high goals, and overcoming life's difficulties
There are fourteen classifications that koi fish can be broken down into, separated by color and markings. One of which is the : Bekko. Bekko can be red, white, or yellow, but will have black markings, like the one I did.