As societies around the world grapple with climate change, they are also facing rising numbers of natural disasters that can deprive residents of clean water, electricity and other lifelines. In response, the Japanese public and private sectors have come together to create solutions for national resilience and disaster prevention. In this article, we highlight two Japanese businesses that represent this effort. They have developed technology and infrastructure services that can be deployed in a flexible manner to ensure continuous access to vital services. These companies are not only contributing efforts toward solving global issues, they are showcasing Japanese innovation and an energized business environment that is open to foreign direct investment.

NIHON GENRYO: Bringing Clean Water Where It’s Needed

At a plant in Takahagi City, north of Tokyo, a pile of sand towers some 15 meters high. It may look like an oversized dune, but the sand is a key component of Japanese technology designed to address water challenges in Japan and around the world. The Takahagi Plant is operated by NIHON GENRYO, whose products are widely used in conventional water purification plants as well as mobile systems designed to provide clean water during disasters and in areas where water infrastructure is limited.

“Water treatment is our business, but we are also a manufacturing company. We want to create new things and bring about a paradigm shift,” says Saito Yasuhiro, President of NIHON GENRYO.

Founded in 1939, NIHON GENRYO now supplies about 80% of the filter media used in water-treatment plants across Japan. The main component is filtration sand, a natural, effective filter media for ensuring the purity and safety of potable water.

The company has also developed ways to recycle filter media rather than continually replacing them. The approach is increasingly relevant as high-quality sand becomes scarcer worldwide, with large quantities used as a raw material for concrete.

“We realized that we could not simply continue using sand and throwing it away,” Saito says. “We needed to find a way to recycle it.”

Compact Filtration With A Siphon System

That philosophy led to the company’s siphon tank, a compact filtration system that can clean its own filter media. Dirty water enters at the top, passes through the filter and emerges as clean water, while a patented mechanism inside the tank periodically cleans the sand.

NIHON GENRYO developed the technology after searching for a better way to remove contaminants that accumulate on filtration sand. Conventional cleaning methods were either ineffective or risked damaging the sand. At Doshisha University, research into “singing sand”—a variety of sand that “squeaks” when walked on due to its high silica and quartz content—provided a breakthrough: experiments showed that sand could be cleaned by making the individual grains rub against one another.

The company developed a screw mechanism that creates vertical and horizontal vortex motion inside the tank, dramatically accelerating the process. A method that initially took about 40 hours was reduced to roughly 15 minutes.

The result was a filtration system in which the media can be repeatedly cleaned rather than discarded. The oldest siphon tank still in operation has run for more than 20 years without requiring its sand to be replaced, according to Saito.

The technology has particular relevance in Japan, where a mature water network is increasingly being challenged by population decline, aging infrastructure and a shortage of engineers. Other challenges include deterioration of raw water quality and frequent natural disasters. Rather than continually building large centralized facilities, NIHON GENRYO believes smaller, movable systems can provide a more flexible alternative.

Its mobile siphon tank combines the filtration technology with the equipment needed to regulate and supply water, creating what is effectively a compact water-treatment plant that can be transported to where it is needed. Between 2005 and 2025, siphon tanks were deployed in 26 disaster-response cases in Japan, while overseas applications have included Laos, the Philippines and Ukraine. The company sees this mobility as increasingly important as communities around the world confront disasters and infrastructure gaps.

“Instead of building another large concrete water plant, we need to think about how we can move water-treatment equipment to where people are,” Saito says.

In Ukraine, NIHON GENRYO has supplied mobile siphon tanks and trained Ukrainian engineers in their operation. The company is also exploring applications in countries including the Philippines and Mexico.

Saito’s greater mission is to rethink water infrastructure itself. NIHON GENRYO’s Water Planet Project envisions mobile and decentralized systems serving communities that cannot easily support conventional water plants.

“Our midterm goal is to help reorganize water infrastructure in Japan and to help the two billion people around the world who do not have access to safe water,” Saito says. “We want to create a new paradigm, not simply copy what other companies are doing.”

Kens: Bringing Power To Communities In Africa And Beyond

For Kawaguchi Nobuhiro, President of Kens Co., the idea that Japanese technology could help address infrastructure gaps in developing countries began with a problem much closer to home.

Kens is the overseas arm of Kawaguchi Steel Industry, a third-generation roofing business founded in 1930 that specializes in large industrial buildings, shopping malls and other structures. Such buildings often have vast spaces without supporting pillars, meaning their roofs need to be both strong and lightweight.

When Kawaguchi began looking for new technologies amid growing interest in environmental issues following the Kyoto Protocol, he became interested in solar power. Conventional solar panels, however, were too heavy for some of the large roofs the company worked on. The emergence of lightweight film-based solar technology offered a potential solution.

“We realized that lightweight solar technology could be a good match for the roofs we were building,” Kawaguchi says. “That led us to acquire new patents and technology and to start thinking about how we could use it in a different way.”

The company eventually took that technology beyond Japan. A visit to Myanmar introduced Kawaguchi to the difficulties faced by countries with limited resources and infrastructure, while a trip to Uganda about 15 years ago made a particularly strong impression.

“There was almost no electricity,” he recalls. “But there were so many children and such a dynamic atmosphere. I began to think that perhaps we could do something with that energy.”

Meeting Rural Electricity Needs

Since then, Kawaguchi has traveled extensively in Africa, where he became increasingly focused on rural communities that are often underserved by national infrastructure programs. Kens was established as the overseas business arm of Kawaguchi Steel Industry with a mission of helping electrify rural Africa and creating better educational opportunities for children.

One of its initiatives is the LED Lantern Charging System (LLCS). Solar-powered charging facilities are installed at elementary schools, where LED lanterns are charged during the day. Children can then take two lanterns home, allowing them to study after dark while also providing light for their families, especially women who use outdoor toilets.

Following deployments in Burkina Faso, the LLCS is now being used in Benin. Kens has provided grant assistance for grassroots projects in six African countries as well as installations for the United Nations Development Programme.

The company has also developed other applications for decentralized solar power. Its Cool Link system converts a 40-foot shipping container into a large solar-powered refrigerator. In communities where unreliable electricity causes food to spoil before it can reach consumers, the system can provide cold storage without relying on a conventional power grid.

In addition, Kens is developing solar-powered multifunctional smart streetlights with integrated Wi-Fi and security cameras. Such systems can provide lighting while extending internet access in communities where connectivity remains limited. Recipients include the International Organization for Migration (IOM) in Benin.

The company’s approach is not limited to Africa. It has developed lightweight portable solar kits for refugee camps and supplies them to United Nations organizations as well as areas affected by Ebola virus in the Democratic Republic of the Congo. Meanwhile, Kens is continuing to explore applications for its technology in regions where conventional infrastructure is difficult to establish.

For Kawaguchi, the challenge is finding ways to fund technology deployment. Kens focuses on rural communities that can be overlooked by central governments, where relatively small amounts of energy can nevertheless have a significant impact on daily life.

“Finance is our biggest challenge,” Kawaguchi says. “We have the technology, but the question is how we can finance these projects and make them sustainable.”

The company is working with organizations including Japan International Cooperation Agency and Japan Bank for International Cooperation to explore ways of incorporating its technologies into government-backed proposals and sovereign lending.

Kens also sees an opportunity to build closer links between Japanese and African communities. It is working with other businesses from Saga Prefecture on potential projects in Benin, including poultry farming and oyster cultivation. Such collaborations could combine energy infrastructure with agriculture, food production and employment, creating benefits that extend beyond electricity itself.

The next step could be to manufacture some of its equipment locally. Kens is considering factories in Uganda and Cote d’Ivoire for products such as Cool Link refrigeration systems and smart streetlights. Local production would reduce the difficulty of transporting equipment, while creating jobs and making maintenance and inventory management easier.

For Kawaguchi, the goal is not only to export Japanese products.

“We want to find out what African people actually need and create opportunities to introduce good products from Japan,” he says. “We also want to create a place where Japanese companies and African communities can have a real dialogue.”

That philosophy reflects the broader potential of decentralized infrastructure. Just as NIHON GENRYO is rethinking water treatment by making it mobile, Kens is seeking to make electricity more accessible without waiting for conventional grids to reach every community. Both approaches draw on Japanese manufacturing expertise while adapting it to the realities of a changing world. In this way, Japanese technology is making a significant contribution to address challenges facing countries around the world.

Note: All Japanese names in this article are given in the traditional Japanese order, with surname first.

To learn more about NIHON GENRYO, click here .

To learn more about Kens, click here .