SHOP PREMIUM JAPANESE KOI FISH ONLINE FROM MARUSEI KOI FARM – HOME OF GIANT VARIETIES AND CHAMPION BLOODLINES

Marusei Koi Farm is a name every serious koi enthusiast knows. Located in the Kawaguchi area of Nagaoka City, Niigata Prefecture, this powerhouse of a farm spans over 100,000 square meters and produces upwards of 200,000 koi each year. Founded in 1960 by Seitaro Hirasawa and now run by his son Yoshiyuki Hirasawa, Marusei has become a global name, synonymous with jumbo koi varieties, vast harvests, and uncompromising quality.

As one of the largest and most productive operations in all of Japan, Marusei doesn’t just raise koi; they shape the standards for what koi can be. With over 200 mud ponds dotting its sprawling grounds, the farm has perfected a breeding program focused on strength, size, and durability, while preserving traditional Japanese koi-farming techniques.

SPECIALISTS IN JUMBO VARIETIES

If there’s one thing Marusei Koi Farm is famous for, it’s producing koi with bulk and body. The farm has earned international recognition for its Chagoi, Benigoi, Mizo Ogon, and Yamabuki varieties, often admired for their powerful frames and calm temperaments. These koi aren’t just large; they’re thick, wide, and impressive in motion.

The scale of their Chagoi and Karashigoi alone makes them standout fish in any pond, and their Ki Utsuri offer striking contrast with bold yellow and black patterns. These aren’t delicate fish—they’re built for presence. What’s more, Marusei’s success with jumbo single-color koi hasn’t come at the expense of variety. They also breed Go-Sanke, Kujaku, Benigoi, Shusui, Hi-Utsuri, and Asagi with equal attention to quality and balance.

YOSHIYUKI HIRASAWA’S HANDS-ON APPROACH

While many large-scale farms are run from afar, Yoshiyuki Hirasawa is involved in every aspect of Marusei’s operation. Known for his relentless work ethic and deep knowledge of koi development, he manages everything from mud pond maintenance to harvest logistics. His commitment is visible not just in the health and growth of the koi, but in the way the farm is run day to day.

This high-touch approach ensures consistency across every season and supports the development of koi that meet show-level standards. Whether you're walking through a conditioning house or observing a harvest, the results of that dedication are everywhere.

MASSIVE FACILITIES WITH HIGH CAPACITY

Marusei isn’t just defined by land and mud ponds; it also features expansive indoor and outdoor conditioning facilities. These high-capacity structures are designed to accommodate thousands of koi at various stages of growth, enabling fine-tuned development and continuous monitoring.

This level of organization makes it one of the most efficient and reliable sources for large shipments of koi to collectors, hobbyists, and dealers worldwide. When you walk through Marusei’s facilities, you’re seeing a koi farm that’s built for both scale and sustainability.

WIDE VARIETY, DEEP QUALITY

Beyond the famous jumbo koi, Marusei produces a wide range of varieties with consistently high standards. Whether you’re drawn to a bright Kujaku or the cool tones of a Shusui, the farm’s commitment to detail shows in every fish. Skin quality, body conformation, and color depth are all carefully monitored throughout each koi’s development cycle.

It’s this mix of high volume and high quality that makes Marusei so unique. Few farms can produce hundreds of thousands of koi annually while maintaining aesthetic consistency and health. Marusei does both, year after year.

ADD JUMBO MARUSEI KOI TO YOUR POND – HAND-SELECTED FOR SIZE, COLOR & BEAUTY

If you need stunning koi, check out our Marusei koi collection, renowned for its immense size and distinct features. Need help shopping? Talk to An Expert Online Now. Or call us at (908) 514-4778 and let us help you choose the ideal koi for you.