As climate change accelerates and cities confront rising environmental risks, innovation in climate technology is becoming a central pillar of global startup ecosystems. Platforms such as SusHi Tech Tokyo, which stands for Sustainable High City Tech, are increasingly highlighting companies working on solutions for energy, infrastructure, circular materials and environmental monitoring.
With hundreds of startups expected to participate in the event, several companies already operating in Japan’s climate innovation ecosystem illustrate the types of technologies likely to attract attention. From satellite monitoring to sustainable materials and next-generation energy systems, these ventures represent a growing wave of climate-focused entrepreneurship.
Here are ten sustainability and climate technology startups worth watching in the broader SusHi Tech ecosystem.
1. Synspective
Sector: Climate monitoring and disaster intelligence
Tokyo-based Synspective is developing synthetic aperture radar satellites that monitor environmental changes on Earth. These satellites can capture imagery regardless of weather conditions or time of day, making them valuable for disaster monitoring and climate risk assessment. The company combines satellite data with analytics platforms to support governments and businesses managing flood risks, landslides and other environmental hazards.
2. Kyoto Fusioneering
Sector: Clean energy / nuclear fusion
Kyoto Fusioneering is working on engineering technologies required for future fusion power plants. Fusion energy has long been viewed as a potential source of carbon-free electricity, and the company has gained recognition as one of the Indo-Pacific region’s leading climate tech startups.
By focusing on plasma systems and reactor engineering, Kyoto Fusioneering aims to support the development of commercial fusion energy infrastructure in the coming decades.
3. Challenergy
Sector: Renewable energy
Japan experiences frequent typhoons, which typically disrupt conventional wind turbines. Startup Challenergy is addressing this challenge by developing a turbine capable of generating electricity even during cyclonic conditions.
The company’s blade-less turbine design uses the Magnus effect to generate power in high winds, potentially allowing regions affected by storms to harness a previously untapped renewable energy resource.
4. TBM
Sector: Sustainable materials
Japanese startup TBM has developed LIMEX, a limestone-based material designed to replace plastic and paper in certain products. The company’s technology aims to reduce dependence on petroleum-based plastics while lowering water consumption in manufacturing processes.
LIMEX is already being used in packaging, containers and stationery products, highlighting the growing market for alternative materials.
5. WOTA Corp
Sector: Water technology
WOTA develops decentralised water recycling systems capable of purifying and reusing water in environments where traditional infrastructure is limited.
Its technology has been deployed in disaster response scenarios and remote locations, demonstrating how water recycling systems can improve resilience in regions affected by natural disasters.
6. Sagri
Sector: Climate-smart agriculture
Agricultural startup Sagri uses satellite imagery and artificial intelligence to analyse soil conditions and improve farming productivity. The company’s technology helps farmers identify soil degradation and optimise fertiliser use, which can improve yields while reducing environmental impact.
As agriculture faces increasing climate pressure, data-driven farming technologies are becoming an important part of climate adaptation strategies.
7. Planet Savers
Sector: Carbon capture
University of Tokyo spin-off Planet Savers is developing direct air capture technology designed to remove carbon dioxide directly from the atmosphere. The company aims to reduce the cost of carbon capture systems while making them scalable for industrial deployment.
Direct air capture remains an emerging technology, but it is gaining increasing attention as a potential tool for achieving net-zero emissions.
8. Helical Fusion
Sector: Fusion energy
Another Japanese startup working on fusion technology is Helical Fusion, which is developing reactor designs aimed at delivering scalable, low-carbon power.
The company represents a new wave of ventures seeking to commercialise fusion energy through innovative engineering approaches.
9. Pirika
Sector: Environmental data platforms
Tokyo-based Pirika operates a digital platform designed to reduce plastic pollution by coordinating clean-up activities and collecting environmental data.
The company’s tools help municipalities and organisations track waste pollution and measure the impact of clean-up initiatives.
10. Fermenstation
Sector: Circular economy
Fermenstation uses fermentation technology to convert unused agricultural or food industry by-products into ethanol and other materials that can be used in cosmetics, food and industrial applications.
The startup’s approach demonstrates how biotechnology can contribute to circular economy models by transforming waste into valuable resources.
Climate Innovation and the Future of Cities
The technologies represented by these startups illustrate the diversity of the climate innovation landscape.
Satellite monitoring systems, renewable energy solutions, water recycling technologies and sustainable materials all contribute to the broader goal of building resilient cities and low-carbon economies.
Events such as SusHi Tech Tokyo are designed to bring these innovators together with investors, policymakers and corporations to accelerate collaboration. The conference’s focus on “Sustainable High City Tech” reflects the growing recognition that climate solutions must be integrated into urban systems, infrastructure and industry.
As cities around the world search for ways to adapt to climate change while reducing emissions, the innovations emerging from startups across Japan and the broader Asia-Pacific region may play an increasingly important role.