Yagenji Koi Farm is a koi breeder in Yamakoshi, Nagaoka, Japan. The owner, Ishihara Daisuke, is a fourth-generation koi farmer who has been producing Nishikigoi (koi) for over 80 years. He breeds mainly Gosanke (Kohaku, Sanke, and Showa) and Shiro Utsuri varieties, but also some other varieties such as Ginrin Kohaku, Ginrin Showa, Goshiki, Kujaku, Kikusui, Asagi, Doitsu Sanke, Karashigoi, and others. He is known for his high-quality koi with excellent body shape, skin quality, and pattern.