Each soybean is beautifully coated with natto bacteria, creating a smooth, delicate stringiness with every pull.
Packed with concentrated umami from the soybeans themselves, this is natto in its purest, most flavorful form—a true game-changer with limitless potential.
The culmination of over a century of fermentation expertise and the passion of our developers.
This is Genki Natto: Mugen.
A Century of Craftsmanship,
The Natto Revolution.
Developer Interview
We’ll introduce the passion behind the development, from the ingredients, natto bacteria, and production methods to the packaging, ways to enjoy, and the shelf life of our product.
Savor the Umami of Soybeans—
We Want You to Enjoy Natto!
Coated with natto bacteria that give it the appearance of being wrapped in traditional straw—lightly dried on the surface with smooth, delicate strands.
The soybeans are completely covered in fermentation culture, creating a white finish with a lightly dry exterior and a firm, chewy center.
This handcrafted flavor, once created by wrapping natto in wara (straw) or kyōgi (thin wood sheets), has been faithfully reproduced using modern automation technology.
We’ve replaced the natural properties of straw with precision engineering—honoring tradition while embracing innovation.
Carefully Selected from Around the World
Domestic Medium-Sized Soybeans
We focused on selecting soybeans that are rich in the sweetness preferred by natto bacteria, have a pleasant aroma, and offer a chewy texture when steamed. Over 50 types of domestic and international soybeans were tested and refined.
In our pursuit of the ultimate natto, we spared no effort and made no compromises.
A Miraculous Encounter
Between Natto Bacteria and Domestic Medium-Sized Soybeans
The relationship between the living natto bacteria and soybeans is truly a once-in-a-lifetime encounter. We evaluated the compatibility with domestic soybeans across various factors—such as how well the bacteria attach, the quality of the stringiness, and the texture when eaten. Through countless combinations of 10 to 15 types of natto bacteria and fermentation methods, we experimented tirelessly until we achieved our ideal natto.
Unique Fermentation
“Vibrant Natto Bacteria Method”
The key to the flavor and quality of natto lies in “fermentation control.”
We take great care to manage the temperature, humidity, and fermentation time, making sure to fully harness the power of the natto bacteria. By doing so, we’ve achieved a level of bacteria attachment that coats the entire natto in a way that has never been seen before.
With careful control of moisture content, the natural flavor of the natto and the umami of the soybeans are concentrated, resulting in a delicious natto that is perfect to eat as-is.
No Film?!
A Container That Defies All Expectations!
In our pursuit of fully coating the natto with bacteria, we challenged ourselves to develop a unique fermentation method. During development, we encountered issues such as condensation forming inside the container. If left unchecked, this condensation could affect the texture and shelf life of the product.
To address this, we carefully tested various sizes and numbers of holes in the top of the container. After much trial and error, we were able to achieve a product without film, which was previously thought to be impossible.
We now use a "Smart Pack" that ensures the natto doesn’t dry out or retain condensation, all while considering environmental sustainability and aligning with SDGs.
No Need for Deception!
Season with Hamamishio to Your Liking.
To fully enjoy the natural flavor of the soybeans and natto, we add nothing unnecessary—that’s the essence of Mugen Natto.
Start by having the first bite as it is, just one bean, then gently stir about five times. After that, season with the included Hamamishio (sea salt) to your liking.
Hamamishio is a salt made from seawater, known for enhancing the natural flavors of ingredients. Its rich mineral content and natural umami elevate the flavor of the natto, bringing out its best.
An Unconventional Shelf Life!
Can Be Stored for Up to 20 Days.
Mugen Natto has a shelf life approximately 1.5 times longer than regular natto. By carefully adjusting the moisture content during fermentation and fine-tuning the maturation of the natto bacteria, we’ve created a deep, rich flavor. At the same time, we’ve revolutionized the process by preventing secondary fermentation after production.
We ensure that Mugen Natto is perfectly crafted at our factory and shipped to you with exceptional freshness.