As part of its Sarrows' sustainability initiative, United Arrows is launching a new collection for the Spring/Summer 2025 season. The company has developed a custom fabric featuring Brewed Protein™ fiber, an innovative material created by Spiber. This new fiber is produced from plant-based ingredients through a microbial fermentation process.
Using this unique fabric, United Arrows has designed a variety of items that will be released across six of its brands. We spoke with representatives from each brand to hear their perspectives on this collaboration and their vision for a more sustainable future.
Photos: Yudai Emmei
Text & Edit: Shoko Matsumoto
As part of our Sarrows sustainability initiative, United Arrows has set a goal to have 50% of our products consciously crafted by 2030.
We are currently at approximately 7%, but as we approach our 50% target, we aim to expand our selection of environmentally conscious products. We are doing this by using recycled and innovative new materials and by reducing the environmental impact of our production process. Through these efforts, we aim to provide our customers with more opportunities to connect with the value of these items.
This latest project, a collaboration across six of our brands, was born as a landmark expression of this commitment. Following our exclusive knitwear collaboration with Batoner in February 2024, we developed an original fabric using Brewed Protein™, a next-generation fiber created by Spiber. Now, in a first-of-its-kind initiative for United Arrows, we are launching products simultaneously across these brands, all of which use this unique material.
Though crafted from a single fabric, each piece reflects the distinct design and worldview of its brand. What vision of the future do they present? We spoke with the directors of each brand to find out.
United Arrows Men: Shoji Uchiyama
To be honest, I wasn't entirely familiar with all the details of Brewed Protein™ fiber, so I was immediately intrigued by this project as an excellent opportunity to learn more. My first impression of the fabric was how approachable it felt. Even though it's an innovative new material, it has a familiarity reminiscent of natural fibers, without any sense of artificiality.
I felt this material would pair well with suits and jackets—core elements of the United Arrows style—allowing us to create a piece of outerwear that is both timeless and versatile enough for any occasion. While the coat has a simple appearance at first glance, we incorporated a drawcord at the waist that balances functionality with the ability to customize the silhouette.
The deep back yoke lends it a traditional feel, but we've added a mesh panel underneath for extra ventilation. The overall silhouette is relaxed but not overly oversized, and we opted for a shorter length to create a lighter, more modern feel. The result is a design based on the classic Balmacaan coat, making it easy to style with dresses and versatile for a wide range of occasions, but with unique, functional details.
Adopting Brewed Protein™ fiber may not create a dramatic shift overnight, but we see it as a significant step in our ongoing commitment to sustainable production.
Beyond the environmental considerations, our mission as a brand is to create items of lasting value. We achieve this by refining the design and balance of our products, assuring they can be cherished for years to come.
Moving forward, we will continue to pursue a balance between environmental responsibility and exceptional quality in everything from material selection to product development.
United Arrows Women: Tomomi Asako
I've been following Brewed Protein™ fiber for some time as a forward-thinking, sustainable material, so I was thrilled when we had the opportunity to begin working with it in a significant way. I'm also very optimistic about the potential of a cross-brand initiative like this, as it allows us to leverage economies of scale.
When I first handled the fabric, I was struck by its firm, crisp texture and the way it sits away from the skin, allowing it to maintain a beautiful silhouette. While a fabric with this texture might typically suggest a more casual design, I felt we could create apparel with an unexpected charm by using its structure to introduce feminine volume and an airy silhouette.
For the items we created, we started with a popular United Arrows design. The outerwear piece has an elegant look thanks to the volume in the sleeves and hem. We used a popular balloon silhouette that creates a dramatic feel, and when zipped closed, the piece can also be worn like a blouse. For the hat, we chose a simple bucket hat design to really let the quality of the fabric stand out. By creating such an unexpected piece, we hope to broaden the appeal of sustainable materials. At the same time, I hope customers will see the versatile styling possibilities in the piece itself.
As a brand, we are also continuing our own sustainability efforts, such as partnering directly with material producers and supporting communities through donation-based initiatives, like the "United Love Project." We look to materials like Spiber's not just to supplement the limited supply of recycled or organic options, but as a way to pioneer new possibilities while reducing our environmental footprint.
I'm proud that through this initiative, we were able to take a step toward the future while fully utilizing the unique characteristics of this material.
Beauty & Youth United Arrows Men: Kyouhei Fujihashi
When I first heard about this project with Brewed Protein™ fiber, I was genuinely excited by the prospect of developing products with such noteworthy material for Beauty & Youth. I had a strong interest in the material itself, but felt it would be challenging to tackle on our own. So, I was thrilled that we could approach it as a collaborative project involving several of our company's brands. When I finally handled the actual fabric, I was impressed by its unique structure and premium feel. I wanted to use these characteristics to offer something new with a relaxed feel, setting it apart from our existing synthetic set-up styles. Specifically, I aimed for a casual design that would feel effortless and integrate easily into daily life, pairing well with essentials like T-shirts and sweatshirts.
For the jacket, we designed a slightly sloped shoulder line to allow the structured Brewed Protein™ fiber to drape naturally on the body. It's unlined, making it a light piece that's easy to throw on. The pants feature a flat-front, semi-wide silhouette, making them easy to wear as separates. We leveraged the fabric's three-dimensional quality to create a piece perfect for everyday use.
We hope that customers will want these pieces simply because they are great clothes. From there, we hope they will develop an appreciation for the project's sustainable aspects. As this awareness grows, it will create a movement that enables us to build a sustainable future together with our customers, which in turn will positively impact the brand.
Sustainable product development is a crucial element for our brand; it's a foundational principle. At the same time, we are dedicated to offering products that will be cherished for years, aiming to balance environmentally friendly practices with high quality. This process may take time, but we are committed to making steady progress and will continue to explore new possibilities for the brand.
Beauty & Youth United Arrows Women: Yuko Konuma
I was aware that a few other brands were early adopters of materials made with Brewed Protein™ fiber. However, I had imagined it would be something we'd work with further down the road. So, I was pleasantly surprised to have the chance to engage with it sooner than expected. I saw it as a great opportunity, especially as I felt a growing need for us to be more proactive in terms of sustainability.
When I actually saw the fabric, it had a subtle sheen and a durable feel. This immediately alleviated any concerns I had about its toughness, and I felt it would be an easy material to work with.
The fabric itself has a simple, fundamental character, so I wanted to give our design a distinct personality. That's why we chose to create a jumpsuit, a silhouette our brand is known for. To elevate the design, we added a contrasting fabric to the collar and the lining of the cuffs. While retaining its workwear-inspired details, we used a leather-like material on the collar and cuffs to give it a more refined, chic feel. The fit is relaxed and allows for easy movement, staying true to its workwear aesthetic, making it perfect for those active, on-the-go days.
Through this project, I hope we will have the opportunity to show our customers an approach to creation that reflects a genuine consideration for the environment—one that goes beyond mere efficiency. We intend to move forward steadily, striking a balance between quality and style while also being mindful of costs. I hope that through projects like this, our customers will gain a deeper understanding of what we stand for as a brand.
H Beauty & Youth Men/Women: Shinya Matsumoto
I think this has become an incredibly compelling project, with six highly creative brands participating, each bringing its distinct personality to the table.
The fabric made with Brewed Protein™ fiber has an impressive texture, reminiscent of classic 1970s 60/40 cloth. While it has a certain natural softness befitting a sustainable material, it also possesses a toughness comparable to traditional fabrics. I felt the strong color palette—based in black, gray, navy, and white—was a reflection of our company's firm commitment to this initiative.
In thinking about how to differentiate ourselves while using the same fabric, we focused on a design that was uniquely H Beauty & Youth. For our men's pieces, the result is a design that appears simple but is highly detailed, retaining elements of workwear while projecting a chic sensibility. We also focused on a high-end, street-casual style, creating a pair of wide, bold-silhouetted detachable pants that convert from full-length to shorts via zippers at the knees. We deliberately incorporated details often seen in luxury brands, which is an expression of our own brand ethos. For women, we created an understated bandeau top and shorts, as well as an edgy, maxi-length dress.
As this is a first-of-its-kind initiative for the company, our primary goal is to build awareness. By using sustainable materials, we demonstrate our company's and brand's commitment to sustainability. We believe this conviction resonates with people and helps our message reach our audience more effectively. Creating distinctive products is key to this, but our ultimate goal is to influence the fashion industry by consistently creating compelling products that incorporate sustainable materials and methods.
Through the strength of our design and the appeal of our brand, we want to introduce sustainable products to a wider audience, even to those who may not be specifically focused on environmental issues.
Steven Alan Men: Masahiko Ito
First off, I was drawn to the concept of this initiative: six brands creating products from the exact same material. When I heard that Brewed Protein™ fiber was created through microbial fermentation without relying on fossil fuels, I imagined a very high-tech texture. In reality, the fabric had a surprisingly natural feel, with a texture that felt very familiar.
When considering how to express the Steven Alan identity with this material, we decided to create one of our signature items: a pair of trousers with a tailored curtain waistband. The defining feature is the contrast between the fabric, which has a feel reminiscent of the 60/40 cloth used by outdoor brands, and the formal, tailored waistband. Even though trousers are a signature item for Steven Alan, they can lack a certain excitement without a distinctive material like this one. By incorporating this detail, which originates from bespoke tailoring, into an otherwise casual trouser, we created an element of surprise that expresses our brand's identity.
As a brand, our focus isn't just on selling a particular design; we value communicating the story and thought process behind a product's creation. I believe this project demonstrates that, regardless of the fabric, we can convey the Steven Alan identity as long as we have a clear vision for the final piece.
When it comes to sustainability, our goal is to take small, manageable steps that we can maintain consistently over time. Steven Alan is now in its 12th year, and we have always actively used natural materials that we can integrate into our collections without forcing them. We don't choose materials simply because they are labeled "sustainable." Rather, if a material that happens to be sustainable is the right one for the product, then we want to use it. While it can be challenging to find sustainable materials that meet our standards and suit the current moment, we will continue to actively seek them out and incorporate them whenever possible.
Steven Alan Women: Takae Fukuyoshi
I feel that sustainability in fashion has many facets, but what I found most impressive about Brewed Protein™ fiber is that it's a scientifically developed, forward-thinking material. The fact that we can now work with a material like this is a real testament to 21st-century progress. I wanted to participate because I believe in actively taking on new challenges and seizing opportunities like this.
The fabric had a natural feel with a subtle, understated texture, almost like a nylon blend. It gave me the impression of a natural fiber created through biotechnology, and it was particularly well-suited to a simple, monochrome approach. At Steven Alan, we typically select materials with a focus on natural fibers, designing to highlight the unique properties of each one. With this fabric, I wanted to take advantage of its water-repellent quality and its less overtly sporty feel compared to typical nylon. The idea was to create a simple shirt jacket that could be worn easily, even on a rainy day. We designed it with a shorter length, making it a versatile and convenient piece that's easy to style for almost any occasion.
I believe we've provided a new option for the wardrobe that also offers an element of intellectual curiosity for those who later learn about the story behind Brewed Protein™ fiber. We find the connection between scientifically developed materials and fashion truly fascinating. Moving forward, we want to continue creating meaningful products that look toward the future, going beyond a superficial approach to sustainability.
Astraet Women: Futoshi Toya
We view this project as a significant step in our commitment to sustainable development, one with the potential to enhance our social impact. Though we begin with a small production run, we are confident that its continuation will lead to a broader collection of mindfully made products and create a positive ripple effect within our community.
When I first handled the fabric, I was struck by its substantial feel—it has a beautiful structure and excellent shape retention. This quality makes it ideal for creating architectural silhouettes. It lends itself particularly well to raw-edge finishes, a detail that allows for couture-inspired construction. We channeled this into an oversized M-65 jacket with cutoff sleeves. The silhouette can be cinched at the waist with a drawcord, creating a graceful, couture-like shape. For now, we are introducing just one style. However, as United Arrows continues this work, an increase in production volume would give Astraet greater versatility and help accelerate our sustainable practices.
By highlighting the distinct character of each brand, we can create clear differentiation and draw more attention to this project as a sustainable initiative. For Astraet, our goal is to pursue these efforts consistently. As our collections grow, we hope to extend a positive influence to an even wider audience. It requires a dedicated effort to create exceptional pieces, even in limited quantities, and to share their story. We are committed to communicating with clarity as we move toward a more positive future for our environment.
Loeff Men & Women: Rika Suzuki
We view this project as a forward-looking step in the storied history of this material. The use of Brewed Protein™ fiber is purposeful in itself, and we believe applying it to our 64 cloth gives the fabric a new and valuable dimension.
From our collection of signature pieces, we chose a unisex jumpsuit that embodies our philosophy: creating clothing to be cherished for years, even decades. We found the sporty nature of the 64 cloth to be a natural pairing with the utilitarian design of a jumpsuit. The result is casual yet polished, featuring a front zipper for added practicality. We also hope this piece can serve as an introduction to Loeff's commitment to sustainability.
While building brand awareness is a gradual process, integrating new materials is a fundamental approach. We are witnessing a broad shift toward sustainable materials across the industry, and we anticipate this trend will continue to grow. At Loeff, we will continue to create clothing that honors our established standards of quality while thoughtfully considering our environmental responsibilities.
This project was realized through a desire to take a pioneering role in sustainability, an initiative centered on the use of Brewed Protein™ fiber. With this conscious approach as a foundation, a collection of distinct items has been created, each reflecting the unique vision and design of its brand. United Arrows will continue to pursue a form of circular fashion that exists in harmony with nature, contributing to a more sustainable world.
