The biggest problems in the fusion supply chain are engineering and Kyoto Fusioneering has over $300M to date to solve them
The Fusion Report covers a lot of different areas regarding commercial fusion energy development, and one of them that we really enjoy is the growth of the fusion supply chain. While the fusion supply chain may not be as exciting as actual fusion development, it is incredibly important to the commercialization of fusion energy. Earlier this week, Kyoto Fusioneering announced the close of its Series D round securing JPY 25.72 billion, approximately $162M (USD), bringing their total funding to $305.9M. While this may not be on the scale of many of the top fusion companies, it is impressive for a company that is dedicated to commercial fusion energy’s supply chain. Below is the press announcement after which we’ll discuss why it is important.
Press Release: Kyoto Fusioneering Secures JPY 25.7 Billion To Build The Systems Every Fusion Power Plant Will Need
TOKYO — 24 August 2026 — Kyoto Fusioneering (KF) today announced the first close of its Series D round, securing JPY 16.72 billion (approx. USD 105 million) in new equity along with access to JPY 9.0 billion (approx. USD 57 million) in credit and loan facilities, for JPY 25.72 billion (approx. USD 162 million) in total. The funds will accelerate the UNITY™ Program, KF’s staged de-risking program spanning Japan, Canada, and the United States, and expand the company’s supply capacity and international operations.
KF’s business is not the fusion reaction itself. It is everything surrounding the reaction to make fusion a commercial power source: the systems that heat the fuel, absorb the energy the reaction throws off, convert that energy into useful forms, and generate and recycle the fuel. Most of the fusion industry is working on the reaction. KF works on the plant that must be built around it, regardless of fusion approach.
Three Countries, One De-Risking Program
KF is addressing two of fusion’s hardest gating risks — the “tritium fuel cycle” and “tritium breeding blanket and thermal cycle” — through separate-effects testing at purpose-built facilities, ahead of full-scale integration. No other program in the world is attempting this at the same scale. At UNITY-1 in Kyoto, construction of the power-generation test plant is largely complete. The facility puts a blanket mockup through the temperatures, pressures and magnetic fields representative of a real plant, and converts the heat it produces into electricity and other high value forms. KF is currently running tests that extract hydrogen isotopes from the circulating loop — the same process that will later recover bred tritium — and from this fall will run integrated tests of power generation and hydrogen production from the high-temperature loop.
At UNITY-2, developed with Canadian Nuclear Laboratories through the Fusion Fuel Cycles Inc. joint venture, a fuel cycle systems are in preliminary testing in Japan using hydrogen and other gases. Tritium-based testing at Chalk River is set to begin within the year, targeting the world’s first demonstration of a continuous, fully integrated D-T fuel cycle using real tritium: injecting fuel, recovering what is not consumed, purifying it and putting it back, without stopping.
At UNITY-3 in Tennessee, developed with Oak Ridge National Laboratory and the U.S. Department of Energy, a module-scale neutron irradiation facility for the tritium breeding blanket is in design, targeting facility completion by the end of 2028. It is designed to be the world’s first demonstration of tritium breeding performance under volumetric D-T fusion neutrons. Once all three are running, KF will be the first company in the world to have tested systems essential for commercial fusion power. This round will go primarily toward accelerating that work.
An Industry Enabler: The Infrastructure Every Fusion Plant Needs
Fusion developers worldwide are pursuing various confinement approaches — from magnetic to inertial confinement devices and everything in between — each differing in how they confine and heat fusion fuel to the point where it fuses. Whichever approaches ultimately reach commercial power generation, they will need the same systems outside the reaction itself. KF builds those systems for the industry as a whole rather than for any one design.
This is why fusion programs around the world already run on KF’s gyrotrons — the high-power microwave tubes that help heat fusion fuel to the temperatures at which it reacts, well over a hundred million degrees. Building on foundational technology developed by Japanese research institutions, KF has pushed gyrotron performance to a world-leading level and paired it with the supply-chain management and precision final assembly needed to deliver products tailored to each project’s specifications. That combination of technical strength and delivery reliability has won KF a steady stream of orders from public and private fusion programs worldwide.
As demand grows, KF will use this funding to build mass-production capacity and a supply system that can respond quickly — putting the industrial base in place before fusion plants start being built, rather than after.
A Five-Country Footprint
KF operates in five countries — Japan (Tokyo; Kyoto; Shiga), the United States (Oak Ridge; Seattle), the United Kingdom (Culham), Germany (Karlsruhe), and Canada (Ottawa; Chalk River) — having raised over JPY 32 billion in cumulative equity funding to date and over JPY 14 billion (approx. USD 88 million) in enterprise-wide life-to-date sales. The Series D investor group spans policy institutions supporting decarbonization and green transformation (GX), major infrastructure operators, government-affiliated financial institutions, and global and crossover investors. That range reflects fusion energy’s growing recognition as a target for cross-border industrial investment. Proceeds will fund the UNITY™ Program, gyrotron mass-production capacity, and KF’s engineering and commercial operations across its five markets.
Funding Overview
- Series D equity raised (first close): JPY 16.72 billion (approx. USD 105 million)
- Cumulative equity raised to date: JPY 32.98 billion (approx. USD 207 million)
- Total credit and loan facilities secured: JPY 9.0 billion (approx. USD 57 million)
* USD figures are provided for reference only and are approximate, based on a JPY/USD exchange rate of approximately 159 as of August 23, 2026.
■ Select* New Equity Investors
- IMM Japan Korea-Japan Fusion Fund Investment Limited Partnership (General Partner: IMM Investment Japan Co., Ltd.)
- SiteGround Capital Ltd.
- GX Acceleration Agency (Organization for the Promotion of Transition to a Decarbonized Growth-Oriented Economic Structure)
- Development Bank of Japan Inc.
- East Japan Railway Company (JR East)
- Minerva Growth Partners, Inc.
*List does not include two additional new investors
■ Existing Equity Investors, Follow-on Investment
- SMBC Venture Capital Co., Ltd.
- Kyoto Capital Partners Co., Ltd.
- JIC Venture Growth Investments Co., Ltd.
- Daiwa Corporate Investment Co., Ltd.
- DBJ Capital Co., Ltd.
- MUFG Bank, Ltd.
■ Select* Debt Financing / Credit Facility Providers
- Sumitomo Mitsui Banking Corporation
- The Kyoto Bank, Ltd.
- Sumitomo Mitsui Trust Bank, Limited
- Mizuho Bank, Ltd.
* List does not include one additional institution
Comment from Representative Director & CEO Satoshi Konishi
We are deeply grateful – not just for the scale of this round, but for the range of investors who joined it. We see it as confidence in KF, and as a sign that fusion energy is moving from research into industrialization. We also take it as recognition of our evolution into a company that, regardless of reactor concept, provides, in an integrated manner, the technologies essential to fusion power demonstration projects worldwide. Since our founding, we have been committed to establishing the core technologies and engineering essential to power generation. With this funding, we will further accelerate that journey. In the long-term challenge of commercializing fusion energy, we will continue working together with partners around the world to build the fusion energy industry.
Why This Announcement From Kyoto Fusioneering Is Important
This combination of equity funding and credit loan facilities more than doubles the capital available to Kyoto Fusioneering (KF), a company dedicated to the commercial fusion energy supply chain. As KF said in the second paragraph of their press release, their business is not the fusion reaction itself; it is everything surrounding the reaction to make fusion a commercial power source. KF is dedicated to the tritium fuel cycle and to the tritium breeding blanket and thermal cycle, two of the hardest problems that fusion companies are facing. With facilities in Kyoto Japan, Chalk River Canada, and Oak Ridge Tennessee, KF will truly be able to help companies in a wide range of fronts, enabling them to start testing their tritium breeding technology by the end of 2028. Furthermore, by turning these facilities into mass production plants will allow KF to supply fusion companies with the capabilities they need without having to develop themselves. The Fusion Report congratulates KF on their accomplishment.
