The Hikari-mujimono is the general name given to koi of a single color on an overall metallic body. The colors may be Yellow gold (Yamabuki), silver (Platinum), orange gold (Orenji) and red gold and etc. In 1921, Sawato Aoki of Takezawa, Niigata used a koi with some golden color on the back as a breeding parent. By the forth or fifth generations, he had produced such dull-metallic varieties as Kin Kabuto, Gin Kabuto and Sakin. He finally succeeded to produce the first Ogon-koi by cross-breeding them with a female koi named ‘Shiro Fuji’. After many years of hard work by Aoki and his son, in 1947 Ogon became a recognized variety of Nishikigoi. At first, their dazzling gorgeous golden koi were greatly prized and commanded super high prices. Today, Ogon are not rare ones, but huge-bodied metallic koi are very popular to koi keepers.