Articles

Revolutionizing Winter with "Warmth Retention," Not "Heat Generation"—Washio's Mochihada® Aims to Create a World Without Cold.

2026.01.05

Since its founding in 1955, Washio Co., Ltd., a manufacturer based in Kakogawa City, Hyogo Prefecture, has operated under the motto, "To eliminate cold from the world." To this end, they have been developing and prototyping their signature Mochihada® series of thermal innerwear.

At the heart of 'Mochihada®' lies a unique, patented technology known as the 'Washio-style raising method.' We spoke with Gaku Washio, President of Washio Co., Ltd., about the distinctive features of 'Mochihada®' and its recent expansion into outerwear.

PROFILE

Gaku Washio

President, Washio Co., Ltd.

Born in 1991 in Hyogo Prefecture. After graduating from university, he joined a company in Kobe and later moved to China by himself, where he helped launch a business importing and selling Japanese sake. Upon learning that his family's business was struggling, he returned to Japan in February 2016 to join Washio Co., Ltd. The company reported a record-breaking deficit in the fiscal year that followed. He implemented sweeping management reforms and successfully guided the company back to profitability within a single year. His diverse activities include launching new brands, running crowdfunding campaigns, and hosting his own radio show.

The Science of Warmth: The Secret Behind the Air-Trapping Loop Structure

The 'Washio-style raising method' is a unique technique where the fabric is brushed to create a nap, but the fiber loops are left intact within the knit. While conventional napped fabrics are made by cutting the loops to create a fluffy surface, this proprietary process involves 'knitting' and 'raising' simultaneously. The uncut loops form an insulating air layer, delivering exceptional warmth and a gentle texture.

Washio explains how it works.

"Most thermal innerwear relies on a 'heat-generating' approach, using the heat of adsorption created when fibers absorb moisture. But 'Mochihada®' doesn't generate heat; it 'retains' it.

By raising the fabric while keeping the loops intact, we create numerous air pockets between the inner and outer surfaces of the material. This layer of air acts as insulation, trapping body heat and blocking cold air from the outside. In essence, it 'retains' your body's natural temperature, so you won't feel excessively hot, and it doesn't interfere with your body's ability to self-regulate temperature."

This method of preserving the pile loops also contributes to the fabric's texture, which inspired the name 'Mochihada®' (meaning 'rice-cake skin' for its softness). In conventional napping, cutting the fibers creates "countless sharp ends," which can cause a "prickly" or itchy sensation against the skin.

In contrast, 'Mochihada®' has no such sharp ends, eliminating any itchiness. Furthermore, it is knitted with a plush, 'bulky yarn,' resulting in an exceptionally soft and fluffy texture.

Moreover, by knitting the fabric from a 'stretch-processed yarn' into a 'pile structure,' it achieves excellent multi-directional stretch (vertically, horizontally, and diagonally). This creates a comfortable fit that moves with your body, never feeling stiff, whether you're active or just relaxing.

"'Mochihada®'s incredible warmth eliminates the need for bulky layers. The thin, lightweight fabric lets you move freely and forget about the cold, making it 'clothing that makes you look forward to winter,'" Washio says proudly. This combination of multifaceted features, not just its thermal properties, is why 'Mochihada®' has been a long-time favorite.

From Innerwear to Outerwear: A Brand's Challenge to Evolve

Since its launch in 1970, the 'Mochihada®' brand has primarily focused on innerwear products like leggings. The shift toward outerwear was driven by a desire to "unleash the full potential of our technology."

"As innerwear, our products faced inherent seasonal limitations. And in our intense focus on function, fashion often took a backseat. I knew that to carry the brand into the future, we had to reach a new audience."

The turning point came in 2017. The company launched a 'Raglan T-shirt' designed for everyday wear on a crowdfunding platform. This was a deliberate attempt to break away from the brand's image as just innerwear and reintroduce 'Mochihada®' technology as a stylish, fashionable item.

The Mochihada® Raglan T-shirt, released in 2017.

As a result, the project was a resounding success, gathering widespread support and proving that the brand could appeal to a whole new customer base.

Building on this success, Mochihada® applied its signature heat-retaining technology, originally developed for innerwear, to everyday items like hoodies and ponchos. This transformation wasn't just about expanding the product line; it was a strategic move to redefine the value of the brand's core technology within the context of modern lifestyles.

A Design Philosophy That Embraces Modern Lifestyles

For Mochihada® to gain acceptance as a fashion item, a radical design overhaul was essential.

"We had released outerwear using Mochihada® fabric in the past, but the designs prioritized function over form and didn't really appeal to fashion-conscious consumers. So, we decided to completely rethink the silhouettes.

For instance, our previous hoodies were very form-fitting and tight. We changed them to a relaxed, boxy silhouette with dropped shoulders, making them perfect for everyday wear around town."

A signature piece, the "MOCHIHADA® TOWN Poncho Coat," features a beautiful drape line with a longer back panel for a comfortable, roomy fit. Meanwhile, the "MOCHIHADA® TOWN Pullover Hoodie" features subtle color variations on the ribbed cuffs and hem for a stylish accent, and its double-layered hood provides extra warmth and a structured, three-dimensional shape.

"The Mochihada® fabric is knit on a one-of-a-kind machine—the only one in the world. It’s based on a sock knitting machine from about 50 years ago that we've uniquely modified. It’s almost like an 'out-of-place artifact'; it can create items that even the most advanced modern machinery can't replicate.

Of course, you can't just buy customization parts off the shelf. Whenever we develop a new product or improve an existing one, we have to create the necessary parts ourselves. Our manufacturing is truly supported by the skill and passion of our artisans."

Washio on the Future Potential of Mochihada®

From innerwear to outerwear. Having undergone a major transformation, Mochihada® is now looking toward its next chapter. Washio is eager to expand the brand into new lifestyle scenarios.

"Recently, we've heard from sauna enthusiasts who told us, 'Your poncho is perfect for wearing after a sauna!' Its excellent heat retention prevents you from getting chilled, and it's also absorbent. This was a use we hadn't even considered, but it's a fascinating perspective.

We're a manufacturer first and foremost, not a fashion brand. So our focus isn't on dictating fashion trends, but on developing items that deliver the unique value of Mochihada® to as many people as possible.

We believe there’s a place for Mochihada® not just in winter outdoor activities and camping, but also within these emerging lifestyles."

Born half a century ago, the "鷲尾式起毛" technique has maintained its timeless value while adapting its form to meet the demands of the era. It has evolved from a product that warms the body as innerwear to one that also warms the heart as fashion. This journey of transformation demonstrates the underlying strength and future adaptability of Japanese craftsmanship.

The journey of Mochihada® is far from over. The day when its warmth fulfills Washio Co., Ltd.'s corporate mission—"to eliminate cold from the world"—may not be far off.