MiRESSO: 10 Key Things You Must Know

Overview

MiRESSO is an innovative startup company headquartered in Misawa, Aomori, Japan, specializing in the production and refining of beryllium, a critical material for nuclear fusion energy. Founded in 2023, MiRESSO’s mission is to unlock the potential of mineral resources by providing a stable and cost-effective supply of beryllium, which is essential for advancing fusion energy technologies. With cutting-edge low-temperature refining technology, the company aims to address the challenges of traditional high-temperature mineral processing methods, contributing to sustainable energy development. This article explores key aspects of MiRESSO, from its technology and funding to its broader impact on fusion energy and mineral refining.

1. Cutting-Edge Low-Temperature Refining Technology

MiRESSO has developed a novel proprietary low-temperature refining technology that enables the extraction of beryllium at about 300°C and atmospheric pressure, a significant departure from conventional methods requiring temperatures around 2,000°C. By combining chemical processing and microwave heating, this process drastically reduces energy consumption and costs, lowers CO2 emissions, and allows efficient, scalable production. This technology not only targets beryllium refining but holds promise for processing other rare metals, enhancing resource efficiency and sustainability across industries.

2. Critical Role of Beryllium in Fusion Energy

Beryllium is a vital neutron multiplier in nuclear fusion reactors. It increases neutron yield, which is necessary to breed tritium fuel within the reactor blanket, enabling sustained fusion reactions. However, global beryllium supply is limited, and conventional production methods are costly and energy-intensive. MiRESSO’s efforts to stabilize and scale up beryllium production address a crucial bottleneck in the commercialization of fusion energy, helping unlock the potential of this clean, abundant power source.

3. Strategic Partnership and Pilot Plant Development

MiRESSO has partnered with Pacific Metals Co., Ltd., leveraging their manufacturing site in Hachinohe, Aomori, to establish a beryllium manufacturing pilot plant named BETA (Beryllium Testing Plant in Aomori). This pilot plant, set to begin production by fiscal year 2027, will demonstrate the scalability of MiRESSO’s technology. Basic plant design is performed in collaboration with JGC Corporation, a leading Japanese EPC firm, marking a critical step towards full-scale commercial production anticipated in the early 2030s.

4. Mission and Vision for Sustainable Mineral Resource Utilization

MiRESSO’s mission is “unlocking the potential of mineral resources to connect a bright future to the next generation,” with a vision focused on contributing to the social implementation of fusion energy by ensuring a stable supply of beryllium. Beyond beryllium, the company is building a technology platform model offering refining process consulting, research and development, and technology licensing to address various mineral refining and recycling challenges.

5. Funding Success and Investor Confidence

Since its founding, MiRESSO has successfully raised significant capital to accelerate its development. The company secured approximately ¥4.28 billion (about USD 28.5 million), including a recent ¥1.83 billion Series A first close led by Spiral Capital, with participation from Pacific Metals and Genesia Ventures. It also benefits from a ¥2 billion grant from the Japanese Ministry of Education, Culture, Sports, Science and Technology’s SBIR Phase 3 program, underscoring strong investor and governmental support for its groundbreaking fusion-related work.

6. Leadership Under CEO Masaru Nakamichi

MiRESSO is led by CEO Masaru Nakamichi, who previously led research and development at Japan’s National Institutes for Quantum Science and Technology (QST). Nakamichi’s expertise in fusion energy materials and mineral refining has been key to developing the company’s innovative technologies and establishing industry partnerships. Under his leadership, MiRESSO has gained recognition, including awards such as the JVCA Special Encouragement Award at the 24th Japan Venture Awards for promising entrepreneurial growth.

7. Applications Beyond Fusion: Aerospace, Medical, and Electronics

While beryllium’s primary market in MiRESSO’s focus is fusion energy, the element’s unique physical properties—lightweight, hardness, and high heat resistance—make it critical for aerospace components, medical devices, and electronic instruments. MiRESSO’s low-temperature refining technology could reduce production costs and environmental impacts in these sectors, supporting broader industrial applications and innovation.

8. Social and Environmental Impact: Towards Carbon Neutrality

MiRESSO’s refining process operates at low temperature and pressure, drastically cutting energy consumption and reducing CO2 emissions compared to traditional high-temperature methods. This sustainable approach aligns with global efforts to reduce industrial carbon footprints and supports Japan’s strategic goal to secure critical mineral resources responsibly. By facilitating energy-efficient material production, MiRESSO contributes to circular economy principles and environmental stewardship.

9. Recognitions and Awards

MiRESSO’s innovation has earned notable recognition, including the 2025 EY Innovative Startup Award, highlighting its pioneering role in fusion energy and mineral refining innovation. The JVCA Special Encouragement Award further acknowledges the company’s potential for significant future growth and its contribution to Japan’s energy technology landscape. Such accolades reinforce MiRESSO’s status as a leader among Japanese startups in the clean energy sector.

10. Future Outlook: Scaling to Meet Fusion Energy Demand

Looking ahead, MiRESSO aims to complete the BETA pilot plant by 2027 and use its results to construct a commercial-scale beryllium production plant capable of supplying around 100 tons annually by the early 2030s. This timeline aligns with the anticipated deployment of prototype fusion reactors (DEMO projects) worldwide. By providing a stable and cost-effective supply of beryllium, MiRESSO seeks to enable fusion power’s transition from experimental to practical, revolutionizing energy generation with clean and virtually limitless power.

Conclusion

MiRESSO represents a remarkable convergence of advanced material science, sustainable technology, and visionary entrepreneurship. Its pioneering low-temperature beryllium refining technology tackles critical challenges in fusion energy development and mineral resource sustainability. With strong leadership, strategic partnerships, and robust funding, MiRESSO is poised to make significant contributions to Japan’s—and the world’s—energy future. As fusion energy inches closer to commercial reality, companies like MiRESSO are essential in ensuring the materials supply chains are equally ready. How MiRESSO’s journey unfolds may well shape the future of clean energy and mineral resource utilization for generations to come.