Starlight Engine has raised JPY 6.06 billion, approximately $37.4 million, in its first external financing round to accelerate development of its Fusion by Advanced Superconducting Tokamak project.
Global Brain led the financing through multiple funds under its management. The round included participation from investors spanning electric utilities, construction, real estate, telecommunications, financial services, materials manufacturing, university-affiliated venture capital and international venture capital.
The investor group included Mitsui Fudosan, KDDI Open Innovation Fund V, Tokyu Construction, Fukoku Mutual Life Insurance, Sony Financial Ventures and Global Brain Frontier, AV, formerly known as Airbus Ventures, Kyoto University Innovation Capital, Keio Innovation Initiative, the Kansai Electric Power Group’s K4V Vital Platform Fund, Daiwa Corporate Investment, Fujikura, Furukawa Electric, Mizuho Bank, Mitsubishi Estate’s BRICKS FUND TOKYO and MUFG Bank.
Starlight Engine plans to use the capital to accelerate engineering design and technology development for the FAST project, which is intended to demonstrate fusion power generation during the 2030s.
The company will also invest in research and development, plant site selection, regulatory compliance, supply-chain development and strategic partnerships.
Additional funding will support the expansion of Starlight Engine’s workforce and organizational capabilities. The company plans to grow to approximately 200 employees during the next two years as it advances toward plant construction.
Starlight Engine was established in April 2025 as a group company of Kyoto Fusioneering. The company is focused on moving fusion technology beyond the research phase and developing practical power plants capable of generating electricity.
The FAST project is a privately led Japanese initiative built around an advanced superconducting tokamak.
Tokamaks use powerful magnetic fields to confine extremely hot plasma inside a doughnut-shaped chamber. The approach is one of the most extensively studied configurations for achieving controlled nuclear fusion.
Fusion occurs when light atomic nuclei combine and release energy. The process is similar to the reaction that powers the sun and has the potential to produce large quantities of electricity without the carbon emissions associated with fossil fuel generation.
FAST is designed to create and sustain burning plasma through deuterium-tritium fusion reactions.
The project also aims to demonstrate an integrated fusion power system combining the reactor with fuel-cycle technologies and systems capable of converting fusion-generated heat into usable energy.
Starlight Engine said the project’s use of the tokamak configuration provides access to decades of scientific research, engineering development and experimental results.
The company is drawing on knowledge generated through projects including the International Thermonuclear Experimental Reactor and JT-60SA, a fusion research initiative jointly operated by Japan and the European Union.
Japan’s established manufacturing, engineering and materials industries are also expected to support the project’s development.
Starlight Engine believes this industrial base can help produce the superconducting magnets, specialized materials, fuel systems, energy-conversion equipment and other components required for a commercial fusion plant.
The FAST project has completed its conceptual design phase and is now progressing through engineering design and preparations for construction.
The financing will allow the company to accelerate detailed design work and resolve technical questions before beginning physical plant development.
Site selection will be another important area of focus. A fusion demonstration facility requires access to land, grid infrastructure, transportation, specialized suppliers and local regulatory support.
Starlight Engine also plans to work with national and local authorities on the regulatory framework required to construct and operate a fusion power facility.
Although fusion does not involve the same chain reaction used in conventional nuclear fission plants, demonstration projects must still address safety, radioactive materials, tritium handling, maintenance and environmental requirements.
Supply-chain development will be critical because many fusion plant components are highly specialized and have not yet been manufactured at commercial scale.
Starlight Engine plans to establish partnerships with companies capable of providing superconducting materials, magnets, power systems, construction services, fuel-cycle technology and precision manufacturing.
The FAST initiative already includes participation from several major Japanese companies and research institutions.
Private-sector participants include Kyoto Fusioneering, Sumitomo Mitsui Banking Corporation, Electric Power Development, also known as J-POWER, JGC Japan, Hitachi, Fujikura, Furukawa Electric, Marubeni, Kajima, Kyocera, Mitsui & Co., Mitsui Fudosan and Mitsubishi Corporation.
The project also works with researchers and universities through industry-academia partnerships.
These relationships include a social collaboration program with the University of Tokyo and joint research initiatives involving Tohoku University, Nagoya University, Kyoto University, Kyushu University and Keio University.
Starlight Engine believes collaboration among private companies, academic institutions, government agencies and local communities will be essential to achieving fusion power generation and eventually deploying commercial plants.
The financing comes as governments and private companies around the world increase investment in fusion technology.
Japan has identified the demonstration of fusion power during the 2030s as a national strategic priority.
Government initiatives are increasingly focused on supporting fusion startups, creating public-private investment roadmaps and moving the sector from scientific research toward industrial development.
Starlight Engine said the participation of investors from several industries reflects the range of capabilities required to build and commercialize fusion power plants.
Utilities can contribute knowledge of electricity generation and grid operations, while construction and real estate companies can support site development and large-scale project execution.
Materials companies can help develop specialized conductors and components, while banks and other financial institutions can support the long-term capital requirements associated with building fusion facilities.
Telecommunications and technology investors may also contribute expertise related to data systems, automation and advanced infrastructure.
The company’s longer-term objective is to create a Japan-originated fusion energy industry that can eventually export technology, equipment and power plant capabilities to international markets.
Starlight Engine plans to integrate the major systems required for fusion electricity generation, including plasma confinement, fuel handling, fuel recycling, heat conversion, safety systems and plant maintenance.
The company also aims to develop commercial plants after completing the FAST demonstration project.
The funding represents Starlight Engine’s first external capital raise since its founding and brings its cumulative financing to JPY 6.06 billion.
