MPower Partners Announces Investment in Ex-Fusion, a Pioneer in Laser Fusion Technology

Jun 5, 2025

MPower Partners Fund, a Japan-based global venture capital fund, has invested in Ex-Fusion Inc. (Osaka, Japan), a startup pioneering laser-based nuclear fusion technology implementation.

In a time where we are tasked with both carbon reduction and energy security, nuclear fusion has been in the spotlight as a potential next-generation energy source. While research and development (R&D) has progressed over the past couple of decades globally, commercial deployment of fusion technology is close to none.

Ex-Fusion is a Japanese startup paving the way for scalable laser-powered fusion energy generation. Combining high-output, high-repetition laser technology, continuous target supply devices, and cutting-edge optical control technology, the company is developing a fast-ignition laser fusion system. As Ex-Fusion’s technology uses seawater-derived deuterium as input and generates no CO2, Ex-Fusion’s innovation holds substantial promise for decarbonizing the energy sector, which is single-handedly the largest contributor to global GHG emissions.

In addition to energy generation, Ex-Fusion is expanding its laser technology applications into other industrial domains, including space debris removal and precision laser processing through collaboration with universities and municipalities. The company hopes to play an active role in creating the next generation of industries built on advanced photonics.

Led by CEO Kazuki Matsuo, Ex-Fusion’s team combines deep academic expertise with a strong commitment to real-world impact. The team’s perseverance and execution capabilities enable it to tackle complex, long-term challenges, such as nuclear fusion, while remaining focused on translating cutting-edge science into practical solutions for society.

Our investment in Ex-Fusion marks the first portfolio company of MPower Partners Fund II L.P. (“Fund II”), for which the first close was announced in May 2025. Ex-Fusion’s laser fusion technology offers an innovative solution to various industries and has the potential to fundamentally strengthen Japan’s resilience in energy security. The company’s mission and technology align closely with “Japan Dynamism,” one of MPower’s new investment themes from Fund II, and we are honored to join Ex-Fusion as a partner in their growth.

Through this investment, we will work closely with Ex-Fusion as the company scales, providing strategic support in business development, policy engagement, and international network building

Comment from Mr. Kazuki Matsuo, CEO

To implement laser fusion as part of our energy system, we need more than just technological capabilities; we need partners with a long-term vision and unwavering belief in our mission. We are incredibly honored to welcome among our partners MPower Partners, who shares our commitment to making a positive impact. At Ex-Fusion, our goal is not simply to develop fusion reactors, but also to create a new industry through photonics — from laser processing to applications in space. Together with MPower, we will continue to push boundaries to solve pressing societal challenges.

Comment from Masatoshi Fukasawa, Partner at MPower Partners

We are pleased to announce our investment in Ex-Fusion. As one of the few companies globally aiming to commercialize laser-based nuclear fusion, Ex-Fusion is leading the way in bringing this next-generation energy technology to market from Japan. This initiative is a meaningful step toward addressing critical global challenges such as decarbonization and energy security. Ex-Fusion’s proprietary technologies — including advanced optical control, continuous target delivery, and high-performance laser systems — also hold significant promise for broader industrial applications beyond energy. What sets Ex-Fusion apart is the team’s ability to execute with resilience, technical excellence, and a clear sense of purpose. We look forward to supporting the company’s journey as a next-generation energy leader from Japan and a key contributor to the global energy transition.

About Ex-Fusion Inc.

  • CEO: Mr. Kazuki Matsuo

  • Established: July 19, 2021

  • Number of Employees: 61 (including part-time, as of May 2025)

  • Location: 2-8 Yamadaoka, Suita-shi, Osaka, 565-0871, Japan

  • Corporate URL: https://ex-fusion.com/

About MPower Partners

MPower Partners is a Japan-based venture capital fund with a mission to empower visionary gamechangers and unlock transformative growth. With our diverse investment team and deep global networks, we identify and support high-potential ventures both in Japan and internationally. We go beyond capital investments by helping drive true and sustainable growth among our portfolio startups via our proprietary ESG framework. On a broader level, as bridge-builders and ecosystem shapers, we hope to leave the Japanese venture capital ecosystem better than we found it, one with more diversity and scale.

Fund website: https://www.mpower-partners.com

For inquiries, please contact: info@mpower-partners.com

This press release has been prepared for the purpose of providing information to qualified institutional investors and potential portfolio companies of the Fund, and is not a disclosure document pursuant to the Financial Instruments and Exchange Act, and does not constitute a solicitation or recommendation to purchase the Fund.

Drawing on decades of hands-on expertise and deep networks in both public and private sectors, MPower Partners provides unparalleled support and access to help startups scale with confidence and clarity.

Let's connect

Building something bold? Contact us about unlocking your next stage of growth.

Copyright MPower 2025

Drawing on decades of hands-on expertise and deep networks in both public and private sectors, MPower Partners provides unparalleled support and access to help startups scale with confidence and clarity.

Let's connect

Building something bold? Contact us about unlocking your next stage of growth.

Copyright MPower 2025

Drawing on decades of hands-on expertise and deep networks in both public and private sectors, MPower Partners provides unparalleled support and access to help startups scale with confidence and clarity.

Let's connect

Building something bold? Contact us about unlocking your next stage of growth.

Copyright MPower 2025