Kyoto Fusioneering develops engineering systems for fusion energy plants, including gyrotron plasma-heating systems, fusion heat-cycle systems, and fusion fuel-cycle systems. The company is advancing integrated test plants UNITY-1 and UNITY-2, with UNITY-1 in the final stage of demonstrating liquid-metal loop power-conversion technology and UNITY-2 slated to begin integrated fuel-cycle demonstration in Canada in 2026. It is a 2019 spinout leveraging Kyoto University research and is actively partnering with research institutions and industry globally. Kyoto Fusioneering also participates in Japan’s FAST commercial-scale fusion demonstration project aimed at power demonstration in the 2030s. The company recently expanded its R&D hub adjacent to its headquarters to test individual fuel-cycle devices and systems. On the business side, it has commercial adoption of its gyrotron system in countries including the UK, US, Germany, and Czechia. Financially, the company reported a new combined equity and debt raise totaling ¥9.38 billion and a cumulative equity financing total of ¥16.26 billion. Kyoto Fusioneering develops fusion-plant equipment and systems including plasma heating devices, heat-extraction blankets, high-performance heat exchangers, and hydrogen-isotope transport pumps. The company is advancing UNITY-1 and UNITY-2 projects, including a UNITY-1 power-test plant now installing major equipment and planning a simulated-environment power demonstration around summer 2025. It has formed a joint company with Canadian Nuclear Laboratories (Fusion Fuel Cycle Inc.) and added industry experts to accelerate a fusion fuel-cycle roadmap. The firm is also developing gyrotron systems with industry–academia collaboration to test high- and multi-frequency oscillation, and is expanding operations through a new European subsidiary (Kyoto Fusioneering Europe Gmb). As of the press release it employed 133 people across headquarters, research centers, and overseas offices. Financially, the company has raised significant capital to date and is directing funds toward technology development, global expansion, hiring, and working capital for large contract execution. Kyoto Fusioneering develops fusion‑energy plant equipment and engineering solutions, including plasma heating systems (gyrotrons), thermal‑cycle and fuel‑cycle systems, high‑performance heat exchangers, and hydrogen‑isotope transfer pumps. Since its 2019 founding based on Kyoto University research, the company has advanced R&D projects such as UNITY‑1 in Japan and UNITY‑2 in Canada (with CNL) to mature its Thermal Cycle and Fuel Cycle technologies. It has strengthened partnerships with public research bodies and academic institutions including UKAEA, CNL, KIT, ORNL, SRNL, and Tsukuba University, and recently won a new gyrotron order from General Atomics in the U.S. The company operates from Tokyo (headquarters), a research site in Uji (Kyoto University Uji campus), and offices/subsidiaries in Reading, UK and Seattle, U.S., and had 124 employees as of April 1, 2024. Kyoto Fusioneering aims to accelerate technology development, build supply chains, and commercialize fusion components globally by leveraging investor expertise. Financially, the company has completed multiple fundraises: the Series C extension added ¥1.56B (15.6億円), bringing Series C cumulative proceeds to 120.6億円 and total cumulative fundraising to 137.4億円. Kyoto Fusioneering is a Japan-based nuclear fusion startup. The company was reported to have raised $79 million in an oversubscribed Series C funding round. The article does not provide details on the participating investors or the breakdown of the financing. No operating metrics, use of proceeds, or future-product plans are described in the coverage. The financing was announced in an Asia Digest that also noted other regional startup rounds. Beyond the Series C amount and its oversubscribed status, no additional financial particulars were included. Kyoto Fusioneering is a fusion energy startup based in Japan that develops plant engineering technologies for fusion reactors, including plasma heating (gyrotrons) and heat extraction (blankets). The company raised 1.33 billion yen ($11.7M) in a Series B and has now raised 1.67 billion yen ($14.7M) to date. It also secured 800 million yen ($7M) in debt financing from Bank of Kyoto, Sumitomo Mitsui Banking Corporation and MUFG Bank. The Series B was supported by existing investors including Coral Capital Co., with participation from Daiwa Corporate Investment, DBJ Capital, JAFCO Group, JGC MIRAI Innovation Fund and JIC Venture Growth Investments. Kyoto Fusioneering will use the funds to accelerate research and expand the business, developing its plant engineering technologies needed for fusion reactor projects. The company has been awarded several contracts to support the U.K. government's STEP prototype reactor program, a development the article describes as key to its future as it expands abroad.

Total raised

$160M

Funding rounds

7

Latest round

Series C

Latest activity

Sep 2025