The Koshiji Kase Koi Farm, also known as Koshiji Koi Farm, is a renowned Koi farm located in Iwada, Nagaoka1. The farm is currently run by Kase Kiyoshi1. They are known for their unique combination of Koi varieties including Doitsu Go Sanke, Showa, Goshiki, Yamatonishiki, Kikusui, Kikokuryu and other varieties.

The farm has a large raising area of 80,000 m. They offer a great selection of Koi and have a yearly production of 20,000 pcs.