Otsuka Koi Farm, also known as Kataoka, is located in Koguriyama, Ojiya, Japan. The farm is run by Yoshikazu Otsuka. They specialize in breeding a variety of Koi, including Goshiki, Asagi, Kage Shiro Utsuri, Ki Utsuri, Aka Matsuba, Ochiba Shigure, Budo Goromo, Goshiki Showa, Kawarimono, Go Sanke, and other varieties.

The farm has a large raising area of 50,000 m. Yoshikazu Otsuka is the third generation in his family to breed Koi. They breed a wide range of Koi, producing 15 different varieties, and they have established a reputation as an excellent Asagi producer. However, they are also well known for their high-quality Goshiki, Showa, and Goshoku Sanke.