There are many silk-based cosmetics available, but none are as lavishly infused with silk as Itoguchi. What makes this possible? The secret lies in the world of the kimono.
Nature’s Second Skin, Silk
Silk is renowned for its benefits to the skin. It contains 18 of the 20 amino acids found in the human body and has a pH level that matches our skin. Its high affinity with the skin is so significant that it’s even used in medical gauze.
Given these qualities, the idea of using silk in cosmetics comes naturally. One key ingredient, sericin, is commonly found in skincare products. Present in raw silk before it’s refined, it closely mirrors the skin’s natural moisturizing factors, offering both hydration and antioxidant benefits. Another ingredient, fibroin, is easily accepted by the body and aids in cell regeneration, making it a promising biomaterial for artificial skin.
Silk is produced from the thread spun by silkworm larvae during metamorphosis from pupa to moth. They create cocoons with threads that exceed one kilometer in length. And in Japan, silk is most famously associated with the traditional artform of kimono.
Tokamachi City in Niigata Prefecture is a region renowned for its traditional kimonos. It is here that a company, which grew through a unique kimono business model, became an industry leader and went on to develop a cosmetics line. Their products, packed with the maximum amount of silk ingredients, have earned recognition as some of the best in the cosmetics world, drawing attention from skincare enthusiasts everywhere. This brand, created by silk experts, is known as Itoguchi.
The exhibition at the Tokamachi City Museum, TOPPAKU. Tokamachi City has a long-standing tradition of using a plant called karamushi to make clothing. This city has a history as a textile-producing region, which served as the foundation for the Echigo-shima silk fabric that became highly fashionable during the Edo period. The fabric’s distinctive feature is the strong twist applied to the silk threads, which creates its signature textured appearance.
The Tōkamachi Kimono Merchant Who Rose from the Bubble Era
If you’re curious about Itoguchi’s cosmetics, the best way to understand their appeal is to try them for yourself. The brand has a storied history with an unexpected origin rooted in the world of kimono. To see how it all began and how it earned its esteemed reputation, let’s go back to 1976.
Japan had just gone through the post-economic-boom era and the oil shock. However, the country quickly recovered from this setback, and entered the bubble economy just a decade later. In Tokamachi City, Niigata Prefecture, a town renowned for its kimono industry second only to Kyoto, Matsuo Okamoto started a kimono wholesale business.
As a dedicated kimono merchant in Echigo, Okamoto noticed that most customers rarely wear their kimonos. When he asked why, many expressed concerns about their kimonos getting dirty or ruined and ultimately becoming unwearable.
Traditionally, Japan had shikkaiya (kimono laundry and repair services) that handled washing and mending kimonos. But during the high-growth period, these services dwindled, leaving only a handful of artisans who specialized in geisha kimonos.
“At the time, the kimono industry had lost any concept of aftercare.”
But could a country really call itself a developed nation if it was selling garments worth a million yen or more without any kind of follow-up support?
Matsuo Okamoto
For seven years, Okamoto visited more than 150 kimono shops across Japan, searching for one that offered aftercare services. He found none. Determined to change this, he sent his employees to train under skilled artisans, mastering the intricate craft of kimono maintenance. He then opened a specialty kimono care shop in Tokamachi City.
But there was a problem. If customers could restore their old kimonos, they wouldn’t need to buy new ones. The industry was unwelcoming, and his business soon faced financial difficulties.
“Handling individual customers one by one was exhausting, and since we were originally wholesalers, we were still pricing at wholesale rates. We ran at a loss for years,” he recalls, reflecting on the struggles.
What kept the business afloat were requests from the tea ceremony community. Word spread, and little by little, the business began to grow.
Kimono stains come in many forms, and simple washing often isn’t enough. Some require color removal and re-dyeing, while others need intricate patterns painted over stains to make them disappear. These techniques demand expert craftsmanship. Yet, when Okamoto pitched aftercare services to kimono shops, they showed little interest. Even the bank eventually cut off his funding.
The company Okamoto founded, Kimono Brain, remains a leading expert in kimono aftercare to this day. Their expertise in seamlessly erasing stains from intricate patterns is nothing short of magical.
The turning point came in 1991 with the collapse of the bubble economy. As kimono sales sharply declined and shops across the country went bankrupt, the industry began to take notice. Inquiries started flooding in, and it became clear that Okamoto’s vision had been right all along.
“Suddenly, I was so busy I didn’t have time to sleep. My name was well-known in the industry, for better or worse,” Okamoto laughs, recalling how more than 1,000 orders poured in.
From that point, he remained at the forefront of the industry. While other companies tried to catch up, Okamoto was always a step ahead. His business grew beyond just kimono aftercare, expanding into services such as inspection, repairs, stain prevention, sewing, recycling, new kimono production, storage, and delivery. It became a one-stop solution for all kimono needs.
He named his company Kimono Brain to honor the skilled artisans whose work had often gone unnoticed. The name reflects his deep respect for their expertise and creative ideas.
When it comes to longevity, Okamoto insists, “The key to keeping this business going is its people.”
Just as the brain governs the human body, Kimono Brain is the driving force behind kimono care. It is a collective of minds dedicated to every detail.
An Industry Built on Silk, Yet No One to Make It
Even in his seventies, Okamoto remains as passionate as ever. At the same time, he is keenly aware of the challenges ahead.
“Unfortunately, the kimono market is shrinking. As long as there are people who need our services, we have to keep going. But to do that, we need another pillar to support the business.”
Establishing a new industry in a rural area to complement Japan’s leading kimono processing business was no easy task. While searching for solutions, Okamoto crossed paths with Professor Fujiyoshi Matsubara, an honorary professor at Kyoto Institute of Technology. Matsubara had been working on eradicating silkworm diseases and developing artificial feed that allows silkworms to be raised year-round.
After 35 years of research, he perfected a method for sterile sericulture. Seeing the potential, Okamoto partnered with Professor Takayuki Nagashima of Tokyo University of Agriculture and secured government support from the Ministry of Economy, Trade, and Industry to turn this breakthrough into a business.
“Fifty years ago, Japan had 2,000 sericulture companies. Today, that number is down to around 180, and most of them are focused on tourism. Even when we talk about domestic silk, it’s often not actually produced here; the raw silk is imported, and only the spinning process takes place in Japan.”
As someone working in the silk industry, Okamoto couldn’t overlook this situation. In 2015, he launched a sterile sericulture project and soon succeeded in producing pure domestic silk. Its quality was rated on par with, or even surpassed, Brazil’s Bratac company (founded in 1920 by Japan’s state-backed Brazil Development Corporation) and their top-tier 5A grade silk. However, the business faced obstacles, as the silk needed to be sold at nearly four times the price of regular silk to be profitable.
“At that time, someone involved in sericulture showed me a joint research paper from Tamagawa University and Saitama Prefecture. The paper suggested that ‘midori-mayu’ (green cocoon) was suitable for cosmetics. He said ‘Okamoto, you’ve already come this far, right? There’s no turning back now. We’ll support you.'”
And so, the green cocoon, which was unsuitable for silk production, was transformed at Kimono Brain for use in cosmetics.
Itoguchi
The raw material for Itoguchi’s cosmetics is the midori-mayu. Raised in a sterile environment and fed a specially formulated, sterile diet that includes mulberry leaves, these silkworms are closer to their natural counterparts than the artificially bred ones typically used for silk production. They produce a yellow-green silk that reflects the pigments of the mulberry leaves.
Although it’s known as green cocoon, the color is a yellowish-green.
Around 30% of the cocoon’s outer layer is rich in sericin, while the remaining 70% is fibroin. After undergoing a meticulous hydrolysis process, these components are used in cosmetics (excluding lotions).
On the left are fibroin and its hydrolyzed form. On the right are the outer layers of the cocoon, which provide the raw material for sericin, along with hydrolyzed sericin. Sericin is highly hydrophilic.
There are no domestic cosmetic manufacturers that offer a fully integrated production process using silkworms, but Itoguchi can use as much silk as they require. Any excess silk or parts of the cocoon that aren’t used are sold to medical companies.
The person in charge of Itoguchi is Gohei Okamoto (left), the son of Matsuo Okamoto. On the right is Reiko Tsujii, who leads product planning and development with a firm belief that women’s voices should be reflected in the cosmetics industry.
Silkworms are highly sensitive to ultraviolet rays, making their cocoons have a high UV protection rate. This unique property is incorporated into Itoguchi’s cosmetics, providing natural UV protection. In fact, the moisturizing cream alone has an SPF of 17, which has been confirmed and is also listed on the packaging.
In addition to the Itoguchi brand, there are several other products, including a fabric softener called ulfada, which Tsujii is holding above. It has received high praise, with many saying it makes regular clothes feel like silk. Interestingly, its ingredients are said to be of cosmetic-grade quality, reflecting the brand’s commitment to excellence.
The collection features the Midori Mayu BODY & HAIR Moist Shampoo, an all-in-one cleanser, along with a moisturizing cream, cleansing milk, foaming face wash, toner, skin protect cream, UV spray, and even a high-concentration sheet mask. The formulas feel lightweight yet intensely hydrating, keeping the skin moisturized and leaving you with a sense of satisfaction that will make you feel that it is all you need.
With such a luxurious concentration of silk ingredients, these products are in a league of their own, offering benefits that no other brand can easily replicate. Try it once, and experience the profound difference.
Itoguchi
https://shop.silklifelab.com/
