The Kobayashi Koi Farm, also known as Marusen-Kobayashi Koi Farm, is a renowned Koi farm located in Uonuma. The farm is currently run by Kobayashi Naoto. They are known for their unique combination of Koi varieties including Shiro Utsuri, Showa and other varieties.

The farm has a large raising area of 30,000 m.