Starlight Engine

What Starlight Engine does

Starlight Engine (Starlight Engine株式会社 / Starlight Engine Ltd.) is a privately-held Japanese fusion energy company founded on April 3, 2025 as the main operating entity for the FAST (Fusion by Advanced Superconducting Tokamak) project. The company is developing a low-aspect-ratio tokamak fusion demonstration device that integrates high-temperature superconducting (HTS) coils, deuterium-tritium burning plasma physics, a closed tritium fuel cycle, fuel breeding blankets, and neutral beam injection heating (targeting 11 MW per unit, 33 MW total). Technical targets include 50–100 MW fusion power output, 1,000-second plasma discharge duration, and 1,000 cumulative hours of full-power operation, with power generation demonstration targeted for the 2030s and construction planned to begin after 2028 following engineering design completion.

The company's business model is anchored on government-funded R&D, public-private partnerships, and corporate sponsored research programs, with eventual commercial revenue expected from plant construction, exports of integrated fusion plant technologies, and technology licensing. It serves three primary segments: Japanese government and regulatory bodies driving national fusion strategy (notably METI's dedicated Fusion Energy Office); academic and research institutions collaborating on plasma physics, device engineering, and fuel cycle design (University of Tokyo, Nagoya, Kyoto, Kyushu, Keio, Tohoku, KEK); and a J-Fusion industrial consortium of heavy industry manufacturers, utilities, plant engineers, trading houses, construction firms, banks, and electronics companies (J-Power, Hitachi, Fujikura, Furukawa Electric, Marubeni, Mitsubishi Corporation, Mitsui & Co., Mitsui Fudosan, Kajima, JGC Japan, SMBC, Kyocera). Kyoto Fusioneering is the core engineering partner, contributing its UNITY-1 and UNITY-2 integrated test facilities for energy conversion and fuel cycle demonstrations.

The go-to-market motion is enterprise field sales directed at government, utilities, plant engineering firms, component suppliers, financial institutions, and host municipalities, supported by participation in academic conferences and a press release cadence via prtimes. Revenue mechanics are pre-revenue grant, partnership, and sponsored research flows today, with no publicly disclosed pricing; the company is funded by Japan's METI (¥60 billion over three years in the FY2025 supplementary budget for fusion startups targeting 2030s demonstration) and contributions from its industrial and academic partner network. The company maintains dual Tokyo offices (Ota-ku headquarters since incorporation and a Marunouchi office opened June 1, 2026) and is led by a new executive team installed April 2026 headed by CEO Kiyotaka Kikuchi, formerly Senior Executive Vice President at Mitsubishi Corporation.

Name

Starlight Engine

Legal name

Starlight Engine株式会社（Starlight Engine Ltd.）

Website

https://sle.energy

Company type

Private

Founded year

2025

Operating status

Operating

Short description

Starlight Engine (Starlight Engine株式会社) is a Japanese fusion energy startup founded April 2025 that leads the FAST low-aspect-ratio tokamak project, targeting deuterium-tritium fusion power generation demonstration in the 2030s for Japanese government, academic, and industrial partners.

Ownership category

akta.pro rank

Product category

Fusion Energy Technology

NAICS

Nuclear Electric Power Generation (221113), Turbine and Turbine Generator Set Units Manufacturing (333611)

SIC

Cogeneration Services & Small Power Producers (4991), Engines & Turbines (3510)

akta.pro primary industry

Power Generation Plant Construction (Thermal, Hydro, Nuclear) (IMAFADAC)

akta.pro secondary industry

Engine Generator & Microgrid Power Plant EPC (Diesel/Gas Recip) (EUAEAAAJ)

Keywords

• Fusion energy development
• Tokamak fusion reactor
• Fusion power plant
• Tritium fuel cycle
• Fusion plant engineering

Headquarters

HQ city

Tokyo

HQ country

Japan

HQ region

Asia

Offices2 records

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Technology or R&D, Personnel, Infrastructure, Operations, Supply Chain

Revenue model

1. Fusion Energy Plant Research and Development: As a pre-revenue company focused on fusion energy demonstration, Starlight Engine generates revenue through government grants, public-private partnerships, and eventually commercial plant construction and technology licensing. The company is currently in R&D phase with the FAST project targeting power generation demonstration in the 2030s.
2. Future Commercial Plant Construction: The company aims to lead the construction of commercial fusion plants and become a private-sector leader in exporting plant technologies and integrated systems internationally.

Go-to-market motion1 record

Distribution channels2 records

Marketing channels4 records

Core offering

Starlight Engine develops and commercializes fusion energy power plant technologies through the FAST (Fusion by Advanced Superconducting Tokamak) project — a low-aspect-ratio tokamak fusion demonstration device designed to achieve fusion power generation in the 2030s. The company conducts R&D on burning plasma control, tritium fuel cycles, fuel breeding blankets, and integrated fusion plant systems, targeting commercial fusion plant construction and technology licensing for international export.

Product overview

Starlight Engine operates as a fusion energy company primarily focused on the FAST (Fusion by Advanced Superconducting Tokamak) project—a low-aspect-ratio tokamak fusion demonstration device. The company drives technology development, business development, fundraising, site selection, and supply chain construction for fusion energy commercialization. FAST aims to demonstrate fusion power generation in the 2030s through integrated systems including D-T burning plasma, energy conversion, tritium fuel cycle, and plant integration technologies.

Differentiator

Problem solved

Functional benefit

Products and services

• FAST (Fusion by Advanced Superconducting Tokamak) A low-aspect-ratio tokamak fusion demonstration project that aims to achieve fusion power generation in the 2030s by generating and sustaining deuterium-tritium burning plasma while demonstrating integrated fusion energy systems including energy conversion, fuel breeding, and maintenance operations. Built for government, utility, and industrial partners engaged in the national fusion energy supply chain.
• Fusion Energy Plant Research and Development Comprehensive R&D services for fusion energy plants, including system integration, tritium fuel cycle demonstration, plasma confinement technology, and commercial plant development capabilities. Provided to government agencies, research institutions, and industrial partners building the Japanese fusion energy industry and supply chain.

Quantifiable outcome

• Target fusion power output of 50-100 MW with 1000-second plasma discharge duration
• +2 more outcomes

Segments3 records

Ideal customer profiles3 records

Technology focussed Yes

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature7 records

Partnerships

24 partnerships are on record, tiered core, major and supporting.

• The University of TokyocoreStrategic or Co-development Partner · 30 April 2026Joint research agreement for divertor plasma research led by Professor Shin Kajita and Assistant Professor Yuki Hayashi. The partnership focuses on establishing optimized divertor designs and operational strategies for FAST through 1D plasma transport simulations.
• Ministry of Economy, Trade and Industry (METI)coreOthers · 30 March 2026METI has established a Fusion Energy Office and allocated 60 billion yen over 3 years in the FY2025 supplementary budget to support R&D by startups aiming for fusion power demonstration in the 2030s.
• Keio UniversitycoreStrategic or Co-development Partner · 7 August 2025Joint research on socio-economic impact of fusion energy including economic ripple effects estimation using multilateral input-output analysis and social acceptance surveys for fusion plant deployment.
• Kyoto UniversitycoreStrategic or Co-development Partner · 19 May 2025Joint research agreement for plasma design with Associate Professor Akinobu Matsuyama. Research explores how plasma geometry, coil configuration, and pressure/current distributions impact fusion tokamak performance using HTS technology.
• Nagoya UniversitycoreStrategic or Co-development Partner · 15 May 2025Joint research agreement for plasma design with Professor Takaaki Fujita, who led JT-60U plasma design achieving Q>1 and JT-60SA plasma design. Research focuses on optimal plasma parameters from plasma physics and reactor engineering perspectives.
• Tokyo University - Fusion System Design Engineering ProgramcoreStrategic or Co-development Partner · 25 April 2025Corporate sponsored research program with Tokyo University and 8 private companies established to build academic and technical frameworks for fusion plant design and cultivate next-generation fusion engineers.
• Kyushu UniversitycoreStrategic or Co-development Partner · 24 April 2025Joint research agreement for device design with Professor Kazuaki Hanada, architect of Asia's largest spherical tokamak QUEST. Partnership leverages extensive plasma-wall interaction data for stable plasma operation in FAST.
• Kyoto FusioneeringcoreStrategic or Co-development Partner · 12 November 2024Kyoto Fusioneering serves as the engineering partner for the FAST project, contributing plant technologies including UNITY-1 and UNITY-2 integrated test facilities for energy conversion and fuel cycle demonstrations. The company leads proprietary technology development for fusion energy plants and supports the FAST conceptual and engineering design process.
• J-Power (Electric Power Development)majorStrategic or Co-development Partner · 12 November 2024Industrial partner participating in the FAST project with involvement in corporate sponsored research programs supporting fusion energy development.
• HitachimajorStrategic or Co-development Partner · 12 November 2024Industrial partner contributing to FAST project through corporate sponsored research and technology development for fusion energy systems.
• FujikuramajorStrategic or Co-development Partner · 12 November 2024Industrial partner in FAST project providing expertise in cable and materials technology for fusion plant development.
• Furukawa ElectricmajorStrategic or Co-development Partner · 12 November 2024Industrial partner contributing to FAST project with expertise in electric wire and cable technology for fusion energy applications.
• MarubenimajorStrategic or Co-development Partner · 12 November 2024Trading company partner in FAST project involved in J-Fusion consortium supporting commercial fusion energy development.
• Mitsubishi CorporationmajorStrategic or Co-development Partner · 12 November 2024Major trading company partner in J-Fusion consortium providing global business development expertise for fusion energy commercialization.
• Mitsui & Co.majorStrategic or Co-development Partner · 12 November 2024Trading company partner in J-Fusion consortium supporting FAST project through industrial expertise and international business connections.
• Mitsui FudosanmajorStrategic or Co-development Partner · 12 November 2024Real estate company partner in J-Fusion consortium contributing to FAST project with expertise in facility development and site preparation.
• Kajima CorporationmajorStrategic or Co-development Partner · 12 November 2024Construction company partner providing expertise in plant construction and safety analysis for fusion energy facilities.
• JGC Japan CorporationmajorStrategic or Co-development Partner · 12 November 2024Plant engineering company partner contributing to FAST project with expertise in process plant design and construction.
• Sumitomo Mitsui Banking CorporationmajorStrategic or Co-development Partner · 12 November 2024Banking partner supporting FAST project through corporate sponsored research and financial advisory for fusion energy development.
• KyoceramajorStrategic or Co-development Partner · 12 November 2024Electronics manufacturer partner in J-Fusion consortium contributing advanced materials and component technology for fusion applications.
• Tokamak EnergysupportingStrategic or Co-development Partner · 12 November 2024International collaboration with UK-based Tokamak Energy, bringing expertise in spherical tokamak development and compact fusion reactor design.
• Princeton Plasma Physics LaboratorysupportingStrategic or Co-development Partner · 12 November 2024International research partnership with US-based PPPL contributing expertise in plasma physics and fusion research.
• General AtomicssupportingStrategic or Co-development Partner · 12 November 2024International collaboration with US company General Atomics, leveraging extensive DIII-D tokamak experience and fusion development expertise.
• Canadian Nuclear LaboratoriessupportingStrategic or Co-development Partner · 12 November 2024International partnership with Canadian Nuclear Laboratories contributing to fusion fuel cycle and materials research.

Scale indicators6 records

Recent moves8 records

Expansion highlights6 records

Direct peers

• Kyoto Fusioneering: Japanese fusion plant engineering company and FAST's core engineering partner, contributing UNITY-1 and UNITY-2 test facilities and plant-systems technology. Comparable because both target fusion plant engineering for the Japanese ecosystem and are co-developing the FAST demonstration.
• General Atomics: US-based energy and defense company operating the DIII-D national tokamak and a FAST international research partner. Comparable as a long-standing tokamak operator contributing plasma physics and fusion engineering expertise to the FAST program.
• Tokamak Energy: UK-based private fusion company developing compact spherical tokamaks with HTS magnets. Starlight Engine has a formal collaboration with Tokamak Energy, and both target low-aspect-ratio, HTS-based compact tokamak architectures.
• Commonwealth Fusion Systems: US-based fusion developer building the SPARC tokamak using HTS magnets and pursuing commercial fusion power. Comparable because both pursue compact tokamak fusion with HTS coils as the core enabling technology, targeting similar net-energy milestones.

Broad incumbents

• ITER Organization: Multinational tokamak demonstration project under construction in France. Comparable as the global benchmark tokamak program; FAST is positioned as Japan's complementary privately-led path that leverages lessons from ITER.

Others

• Princeton Plasma Physics Laboratory (PPPL): US Department of Energy national laboratory and FAST international research partner. Comparable as a leading plasma physics research institution contributing knowledge to FAST's plasma and divertor design work.
• Canadian Nuclear Laboratories: Canadian nuclear science organization and FAST international partner contributing to tritium fuel cycle and materials research. Comparable because tritium handling and fusion materials are core FAST scope items.

Emerging players

• TAE Technologies: US-based fusion developer pursuing field-reversed configuration with plans for a commercial fusion pilot in the early 2030s. Comparable as a private fusion peer targeting commercial demonstration on a similar timeline, though using a different confinement approach.
• Helion Energy: US-based fusion developer pursuing pulsed field-reversed configuration with commercial PPAs already signed. Comparable as a well-capitalized private fusion peer targeting commercial electricity generation in the early 2030s.

Regional players

• Korea Institute of Fusion Energy (KFE): South Korea's national fusion research institute operating the KSTAR tokamak and pursuing a Korean DEMO roadmap. Comparable as another Asia-Pacific government-backed tokamak program pursuing commercial fusion on a similar timeline.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat6 records

Key risks6 records

Key highlights7 records

Customer concentration

Revenue estimate

Valuation estimate

Number of profiles

Profiles5 records

Funding overview

Funding rounds2 records

Investors18 records

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Starlight Engine