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 perseverance 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.

• It means good fortune or luck.
• Symbolic in the Buddhism to represent courage. Humans "swim" through the "ocean of suffering" without fear, just like a fish swims through water.
• The koi is symbolic with family. On Children's Day koi flags are raised:
  • Black koi, the father
  • Orange/Red, the mother
  • Blue/White for a boy
  • Red/pink for a girl.
• There is another word to describe "love" which is "koi". The kanji character for "kokoro (heart)" is included as part of both kanji characters. Both "ai" and "koi" are probably translated as "love" in English. However, they have slightly different nuance: "Koi" is a love for the opposite sex, or a longing feeling for a specific person. It can be described as "romantic love" or "passionate love". While "ai" has the same meaning as "koi," it also has a definition of a general feeling of love. "Koi" can be selfish, but "ai" is a real love. Here are some lines that explain them well: Koi is always wanting. Ai is always giving."
• A koi tattoo is supposed to represent different things it just depends on the color and the amount of them and the direction they are swimming in the stream. 5 golden koi is supposed to represent eternal wealth and well being. Each color represents a specific meaning. Some people believe that the color of Koi Tattoo on your body should be in harmony with you and your surroundings.
• In general koi are associated with good luck, plain and simple. The colors and size doesn't mean anything.