From Outdoor Gear Rental to Revolutionary Water Repellent Technology: The Story Behind Droproof

How one entrepreneur's frustration with wet rain gear led to the development of a groundbreaking water repellent coating service

When you think of innovation in the outdoor industry, you might picture high-tech fabrics or cutting-edge equipment design. But sometimes, the most impactful innovations come from solving everyday frustrations that passionate outdoors enthusiasts encounter in the field.

This is exactly what happened when Takanori Murono, CEO of "SORANOSHITA" (Japan's pioneering and largest outdoor gear rental company), launched Droproof – a specialized water repellent treatment service that's changing how we think about gear maintenance and performance.

The Moment That Sparked Innovation

The story of Droproof begins with a soggy disappointment. Murono recalls the pivotal moment that would eventually lead to this revolutionary service:

"During busy seasons, I would help with maintenance, washing boots and cleaning gear. One day, when rain gear rented for a Mount Fuji climb was returned completely soaked, I felt frustrated as a rental professional and maintenance expert. The customer had encountered bad weather – which is completely understandable – but I wondered: couldn't we create rain gear that would keep climbers completely dry, even on Mount Fuji?"

This wasn't just about customer satisfaction. Murono recognized that highly water-repellent gear directly contributes to safety. When clothing absorbs water, it becomes heavier and allows cold to penetrate, potentially creating dangerous situations for outdoor enthusiasts.

"By improving water repellency, we could make outdoor activities not only safer but also more comfortable," he explains. "As outdoor maintenance professionals, we decided to seriously tackle the challenge of maintaining water repellency."

The Technical Challenge: Coating What's Already Coated

What sounds like a straightforward problem turned out to be a complex engineering challenge. The biggest hurdle? Most outdoor gear already has water repellent treatments applied during manufacturing.

"The fundamental issue was that we were trying to treat items that already had water repellent processing," Murono explains. "When we tried to apply additional water repellent agents, they would be repelled by the existing treatment and wouldn't adhere properly."

Even when the team managed to achieve improved water repellency, they faced another problem: the effects weren't lasting long enough to be practical for serious outdoor use.

Beyond Quick Fixes: The Pursuit of Long-Lasting Performance

Unlike many water repellent treatments that offer temporary solutions, the Droproof team focused on what they call "sustainable water repellency." Murono emphasizes that while restoring initial water repellency isn't particularly difficult, creating long-lasting performance is where the real challenge lies.

"Initial water repellency might be high, but that doesn't guarantee long-term durability. Long-term sustainability was our biggest challenge. Our ultimate goal was to maintain comfort and safety even under harsh conditions."

Rigorous Testing and Validation

To ensure their "Bullet-Water Coating®" technology met the highest standards, the Droproof team implemented comprehensive testing protocols:

• JIS Standard Compliance: They adopted Japan Industrial Standards (JIS) water repellency tests as their baseline
• Proprietary Durability Testing: Recognizing that standard tests weren't sufficient, they developed their own evaluation methods for water repellent durability
• Third-Party Verification: External research institutions were engaged to validate both water repellency and durability performance

This multi-layered approach to testing reflects the company's commitment to delivering measurable, reliable results rather than making unsubstantiated claims.

The Developer's Mindset: Never Give Up on Innovation

What sustained Murono through the inevitable setbacks and technical challenges? His background as an engineer at Daikin Industries (one of only two fluorine manufacturing companies in Japan) certainly helped, but it was his developer's mentality that proved most valuable.

"I have a technical background, so I understood how to conduct research. I was confident that with enough trial and error, we could restore water repellency," he reflects. "My motivation comes from wanting to bring something completely new to the world. I believe there are people who will appreciate this innovation, and for their sake, I couldn't give up, no matter what problems we encountered."

Beyond Mountain Gear: The Future of Droproof

While Droproof currently focuses on mountaineering equipment, Murono has bigger ambitions for the technology. The company's approach reflects a philosophy common in outdoor innovation: solutions developed for extreme mountain conditions often find applications in everyday life.

"We've started with mountaineering gear, but I hope to apply this reprocessing technology to other areas in the future. Mountain technology has historically found applications in many other fields, so I'd like to explore how our bullet-water coating could benefit other industries as well."

The Professional Behind the Innovation

Murono's unique background makes him particularly suited to tackle this challenge. After graduating from university, he joined Daikin Industries as an engineer working in development while simultaneously learning mountaineering fundamentals as a member of the Senshu Mountaineering Club.

In 2010, he launched SORANOSHITAas a sole proprietorship, becoming the first in Japan to offer internet-based rental services for mountaineering and outdoor equipment. The company was incorporated in 2012, with Murono serving as CEO.

His credentials span both technical and outdoor expertise:

• Certified Mountain Guide (Stage II) and Nature Guide (Stage I) by the Japan Mountain Guide Association
• Camp Instructor certified by both the Japan Camping Association and Japan Auto Camping Association
• Licensed cleaning specialist and high-pressure gas manufacturing safety supervisor

What This Means for Outdoor Enthusiasts

The development of Droproof represents more than just another gear service – it's an example of how deep industry expertise combined with genuine passion for outdoor activities can lead to meaningful innovation. For outdoor enthusiasts, this means:

Enhanced Safety: Gear that maintains water repellency longer reduces the risk of hypothermia and other weather-related dangers

Improved Comfort: Consistently dry gear means more enjoyable outdoor experiences, regardless of weather conditions

Extended Gear Life: Professional maintenance and reprocessing can extend the useful life of expensive outdoor equipment

Performance Reliability: Knowing your gear will perform when you need it most provides peace of mind for serious adventures

The story of Droproof reminds us that some of the most impactful innovations come not from dramatic breakthroughs, but from the persistent effort to solve real problems faced by people who are genuinely passionate about what they do. In an industry where gear performance can literally be a matter of life and death, that dedication to continuous improvement makes all the difference.