Marusaka

Marusaka Koi Farm (丸坂養鯉場 – Marusaka Yōriba)

For over 70 years, Marusaka Koi Farm has stood as a multi-generational pillar of Japanese koi breeding. Founded around 1948 by Teruchiyo Hiroi, refined by his successor Teruo, and now led by Teruyuki Hiroi, this family-run farm has grown from tradition into a cornerstone of Niigata’s koi heritage.

Marusaka’s roots are deeply planted in Ojiya—known as the birthplace of Nishikigoi. The Hiroi family’s dedication over three generations has elevated the farm’s reputation for both excellence and diversity in koi breeding. Under Teruyuki’s stewardship, the farm continues to push boundaries while honoring time-tested methods.

Marusaka is renowned for its wide array of metallic koi, offering exceptional variety and artistry. Key specialties include:

• Kin Kikokuryu, Kikokuryu, Kujyaku, and Lemon Hariwake
• Doitsu Kohaku, Doitsu Sanke, Sanke
• Midorigoi, Ginrin Chagoi, and more

A particular point of pride is the Marusaka Sanke bloodline, a champion lineage recognized for winning top prizes—including Young and Mature championships—at the All Japan Nishikigoi Show early in its history

• Located in Minaminigoro, Ojiya, with ideal koi-breeding conditions
• Boasts around 80 mud ponds, 20 parent-stock koi, and a yearly production output of approximately 55,000 koi
• Family-oriented operations: the entire Hiroi family contributes to daily koi farming efforts
• Heritage: Three generations of breeding excellence rooted in Niigata, the heartland of Nishikigoi
• Diversity: A broad selection of metallic and traditional varieties for all koi enthusiasts
• Reputation: The Marusaka Sanke line is nationally celebrated for competitive quality
• Scale & Commitment: Large-scale production without sacrificing artful detail or craftsmanship