Investment in Commonwealth Fusion Systems
～Launching collaboration toward the early commercialization and industrialization of fusion energy power generation in Japan～

TOKYO - September 2, 2025 - NTT, Inc. (Headquarters: Chiyoda, Tokyo; President and CEO: Akira Shimada; hereinafter "NTT") has participated in an investment in U.S.-based Commonwealth Fusion Systems LLC (Headquarters: Massachusetts, USA; Co-founder and CEO: Bob Mumgaard; hereinafter "CFS"), a company engaged in fusion energy, through a fund managed by NTT DOCOMO Ventures, Inc. (Headquarters: Minato, Tokyo; President, CEO, and CCO: Yuko Sasahara; hereinafter "NDV"). The investment was made in collaboration with a consortium of 12 Japanese companies¹.

Background

The NTT Group aims to leverage AI and digital technologies to make society more convenient and prosperous. At the same time, with the rapid adoption of AI, the power consumption of data centers is expected to increase severalfold, posing a serious challenge of growing electricity demand.

Through the promotion of the IOWN initiative², the NTT Group is working to reduce the power consumption of information processing infrastructure, while recognizing the importance of advancing the realization of sustainable and clean energy. Among the various options, the Group sees great potential in fusion energy power generation, a next-generation energy source with extremely low environmental impact.

CFS is the world's leading and largest private fusion company, utilizing the magnetic confinement system (tokamak type)³. The company announced plans to build the world's first commercial fusion power plant "ARC" in Virginia in the United States, with the intent of commencing operations in the early 2030s.

The Japanese Consortium will acquire technical and commercial expertise in policy, regulatory, and the development, construction, operation, and maintenance of ARC from CFS's commercialization projects in the United States. In addition, each consortium will bring together its know-how and expertise and aspire to expedite the commercialization and industrialization of fusion energy power generation in Japan.

The collaboration between the Japanese Consortium and CFS is in line with the Japan - U.S. joint partnership to accelerate the development and commercialization of fusion energy power generation in Japan and the United States, and represents a strong commitment and growing momentum toward the early realization of commercialization in both countries.

Investment

Company Name: Commonwealth Fusion Systems LLC
Co-founder & CEO: Bob Mumgaard
Headquarters: Massachusetts, USA
Business Overview: Manufacturing and service provision of fusion energy power plants utilizing the magnetic confinement system (tokamak type)
URL: https://cfs.energy/

Outlook

The NTT Group views its investment in CFS and participation in the Japanese Consortium as highly significant in contributing to the commercialization of fusion energy power generation. Leveraging the Group's technological expertise, we will actively work to accelerate the social implementation of fusion energy power generation.

¹Consortium members: NTT, Inc.; MITSUI & CO., LTD.; Mitsubishi Corporation; The Kansai Electric Power Co., Inc.; JERA Co., Inc.; Mitsui O.S.K. Lines Ltd.; JGC JAPAN CORPORATION; Development Bank of Japan Inc.; Fujikura Ltd.; Sumitomo Mitsui Banking Corporation; Sumitomo Mitsui Trust Bank Ltd.; Mitsui Fudosan Co., Ltd.

²The IOWN (Innovative Optical and Wireless Network) is an initiative for networks and information processing infrastructure including terminals that can provide high-speed, high-capacity communication utilizing innovative technology focused on optics, as well as tremendous computational resources. For more information, please visit our website.
■What is the IOWN Initiative?
URL: https://www.rd.ntt/e/iown

³A torus-shaped fusion energy device that uses a strong magnetic field to confine ultra-high temperature plasma.

About NTT

NTT contributes to a sustainable society through the power of innovation. We are a leading global technology company providing services to consumers and businesses as a mobile operator, infrastructure, networks, applications, and consulting provider. Our offerings include digital business consulting, managed application services, workplace and cloud solutions, data center and edge computing, all supported by our deep global industry expertise. We are over $90B in revenue and 340,000 employees, with $3B in annual R&D investments. Our operations span across 80+ countries and regions, allowing us to serve clients in over 190 of them. We serve over 75% of Fortune Global 100 companies, thousands of other enterprise and government clients and millions of consumers.