Because this has the meaning of attracting wealth.
The eight koi fish have the meaning of bringing wealth from all directions. This pattern is usually found on cross stitches or New Year pictures. Koi carp originated in Central Asia and was later introduced to China. In ancient China, palace technicians cultivated goldfish according to this method.
The mutant varieties selected by the golden crucian carp method to meet public aesthetics were introduced to Japan in modern times and have been carried forward in Japan. Many excellent varieties were developed in Japan, and therefore many koi are named with Japanese names. It is the national fish of Japan and is known as the "living gem in the water" and the "king of ornamental fish". Koi has a strong physique, bright colors, changeable patterns, and majestic swimming postures. It has extremely high ornamental and breeding value. Its body length can reach 1-1.5 meters, and its lifespan is also extremely long. It can live 60-70 years (it is said that there is a 200-year-old koi). It means good luck and is said to bring good luck to its owner. It is a popular Feng Shui fish. and ornamental pets.