Two koi fish symbolize "the joyous union of fish and water", which implies a happy marriage and family harmony. In folk customs, keeping two koi fish, especially in the room of newlywed couples, represents the deep affection between husband and wife and their harmonious coexistence, hoping for a happy and fulfilling family life.
The swimming posture of koi fish is elegant, and their colors are gorgeous. They are often regarded as symbols of family harmony and harmonious interpersonal relationships. When two koi fish are together, it implies a harmonious and happy family as well as harmonious interpersonal relationships.