Top 10 Quantum Computing Companies in Japan

Japan is quietly building one of the world's most complete quantum ecosystems — spanning superconducting processors, cold neutral-atom hardware, cryogenic materials, quantum software, and pharma-grade quantum chemistry. According to QuantumNews' Japan country page, the ecosystem now counts 52 companies, 8 university research clusters, and 1 national research institution, concentrated heavily around Tokyo (35 companies), with smaller hubs in Osaka, Wako, Yokohama, Chigasaki, Kyoto, Hamamatsu, and Tsukuba.

1) Fujitsu

Company link: https://quantumnews.in/company/fujitsu Quantum Score: 55 | Headquarters: Tokyo, Japan | Focus: Hardware | Qubit Tech: Superconducting (RIKEN collaboration)

Here's a deep dive into the Top 10 Japanese quantum computing companies, ranked by their QuantumNews Quantum Score — a composite measure of hardware scale, gate fidelity/error-correction maturity, funding raised & investor quality, and commercial momentum & partnerships.

Fujitsu is ranked number one on the QuantumNews Japan company list with a Quantum Score of 55. The company is positioned as the strongest quantum computing player in the Japanese ecosystem, building both quantum annealing systems (marketed as the Digital Annealer) and superconducting gate-model quantum computers.

According to its QuantumNews profile, Fujitsu operates a 256-qubit superconducting quantum computer at the RIKEN RQC-Fujitsu Collaboration Center, unveiled in April 2025 as a 4× upgrade from the previous 64-qubit system. A 1,000-qubit system is planned for 2026, with more than 10,000 qubits targeted by 2030. Fujitsu also took part in the launch of the University of Osaka’s domestically produced quantum computer in July 2025 and offers cloud access to quantum simulators and hybrid quantum-classical computing through Fujitsu Quantum Computing as a Service. In May 2025 the company deployed its Digital Annealer with Toyota Systems for automotive connector design, achieving 20× acceleration over conventional methods while running on mass-produced ECUs.

What makes Fujitsu important is that it combines large-scale superconducting hardware development, annealing systems already in industrial use, hybrid cloud services, and deep national research partnerships. Application areas listed include optimization, drug discovery and materials science. For anyone studying the Japanese quantum ecosystem, Fujitsu is the anchor company: it represents the high end of the country’s superconducting ambition, industrial application focus, and long-term scale-up roadmap.

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2) QunaSys

Company link: https://quantumnews.in/company/qunasys Quantum Score: 35 | Headquarters: Tokyo, Japan | Focus: Software | Funding: $29.7M+ raised

QunaSys is the highest-ranked pure software company on the Japan list. Founded in 2018, it specialises in quantum chemistry software and molecular simulation. Its QuantumNews profile describes the development of quantum algorithms and computational tools for chemical and pharmaceutical research, materials science and drug discovery.

QunaSys raised $29.7M from Global Brain, JIC Venture Growth, Mitsubishi Electric and Zeon Corporation. It has launched the QSCI Technical Portal and an official partner programme, licensing its quantum-enhanced molecular simulation platform to pharmaceutical companies. Commercial partners include Biogen, Dow Chemical and Accenture. The company’s QSCI (Quantum-Selected Configuration Interaction) algorithm is being extended beyond quantum chemistry into optimization problems.

QunaSys is important because it supplies the application-layer software that turns quantum hardware into practical tools for Japan’s strong pharmaceutical and materials industries. Its commercial traction and algorithm focus make it the clearest software leader in the ranking.

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3) Anritsu

Company link: https://quantumnews.in/company/anritsu Quantum Score: 30 | Headquarters: Atsugi, Japan | Focus: Hardware

Anritsu Corporation is a long-established Japanese manufacturer of telecommunications test and measurement equipment (founded 1895). Its QuantumNews profile highlights test equipment for quantum communication systems, including optical network analyzers, signal analyzers and specialised instruments for validating quantum key distribution (QKD) networks and quantum communication infrastructure. The company also develops testing solutions for quantum-safe telecommunications and post-quantum cryptography.

Anritsu serves telecommunications operators, quantum technology companies, research institutions and quantum network developers. Application areas listed are quantum key distribution, quantum networking and post-quantum cryptography.

Anritsu is important because quantum networking and quantum-safe communications require precise measurement and validation equipment. The company supplies critical enabling infrastructure rather than processors themselves.

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4) Blueqat Inc.

Company link: https://quantumnews.in/company/blueqat-inc Quantum Score: 30 | Headquarters: Tokyo, Japan | Focus: Software | Qubit Tech: Neutral atom | Est. 2018

Blueqat is a Japanese quantum computing startup partnering with the Institute for Molecular Science to develop Japan’s first cold neutral atom quantum computers, with commercialization targeted by 2024. The company combines quantum hardware development with open-source quantum software tools to advance accessibility in Japan. Its profile states that Blueqat forms part of Japan’s national strategy to achieve quantum computing independence through domestic cold-atom technology.

Application areas include materials science, drug discovery and optimization. Sectors listed are neutral atom, quantum processors, quantum software, quantum hardware and quantum research.

Blueqat is important because it represents Japan’s push into neutral-atom hardware as a complementary pathway to the dominant superconducting efforts, while also contributing open-source software tools.

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5) Faraday Factory Japan

Company link: https://quantumnews.in/company/faraday-factory-japan Quantum Score: 30 | Headquarters: Tokyo, Japan | Focus: Hardware | Est. 2015

Faraday Factory Japan develops cost-effective mass-production methods for High Temperature Superconducting (HTS) tapes, with production capacities approaching 100 thousand kilometres per year. It produces second-generation HTS wire using advanced manufacturing processes that reduce costs and increase availability of superconducting materials for quantum computing applications.

The company manufactures superconducting tape used in superconducting qubits, quantum interconnects and cryogenic quantum systems. It serves quantum computing manufacturers, research institutions, cryogenic equipment providers and quantum technology companies that need high-volume, cost-effective superconducting wire.

Faraday Factory Japan is important because scalable superconducting quantum computers require large volumes of high-quality superconducting materials. The company’s mass-production focus addresses a critical supply-chain bottleneck.

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6) Fixstars Amplify

Company link: https://quantumnews.in/company/fixstars-amplify Quantum Score: 30 | Headquarters: Tokyo, Japan | Focus: Hardware (platform) | Est. 2021

Fixstars Amplify offers a cloud platform built for combinatorial optimization problems that integrates quantum annealing, Ising machines and gate-model quantum computers. The platform provides an SDK and execution environment that automates logical-to-physical model conversion and machine execution, making quantum annealing programming more accessible. It is compatible with the company’s own Fixstars Amplify Annealing Engine (AE) as well as all available quantum annealing and Ising solvers, mathematical optimization solvers and gate-based quantum computers. The GPU-based Amplify AE processes large-scale problems of more than 100,000 bits at high speed.

Since becoming publicly available in 2021, Amplify has processed more than 45 million user requests (as of October 2024). It has been adopted in the Mitou Target Program and also offers Toshiba’s Quantum-Inspired Optimization Solution SQBM+.

Fixstars Amplify is important because it lowers the barrier to using annealing and hybrid optimization hardware, turning specialised quantum and quantum-inspired machines into accessible cloud services for enterprise users.

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7) Fuji Electric

Company link: https://quantumnews.in/company/fuji-electric Quantum Score: 30 | Headquarters: Tokyo, Japan | Focus: Hardware | Est. 1923

Fuji Electric Co. Ltd. is a major Japanese electrical equipment manufacturer that produces superconducting materials and components for quantum computing and power applications. It manufactures superconducting wires, cables and systems using both Low Temperature Superconductor (LTS) and High Temperature Superconductor (HTS) technologies.

The company provides superconducting solutions for quantum computing infrastructure, including cryogenic systems, superconducting magnets and power-conditioning equipment used with quantum processors. It serves quantum technology companies, research institutions and cryogenic equipment manufacturers.

Fuji Electric is important as a long-established industrial supplier of the superconducting materials and cryogenic infrastructure that superconducting quantum systems depend on.

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8) Fujikura

Company link: https://quantumnews.in/company/fujikura Quantum Score: 30 | Headquarters: Tokyo, Japan | Focus: Hardware

Fujikura Ltd. (founded 1885) produces superconducting wires, cables and materials for quantum computing and telecommunications. Drawing on more than 135 years of cable and wire manufacturing expertise, the company manufactures high-temperature superconducting (HTS) wire and cable products.

Fujikura’s superconducting solutions support quantum processors, superconducting qubits, quantum interconnects and cryogenic quantum systems that require ultra-low-resistance electrical conductivity at cryogenic temperatures. It serves quantum computing manufacturers, research institutions, telecommunications companies and cryogenic equipment providers.

Fujikura is important because high-performance superconducting interconnects and wiring are essential for scaling quantum processors and building reliable cryogenic systems.

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9) Hamamatsu Photonics

Company link: https://quantumnews.in/company/hamamatsu-photonics Quantum Score: 30 | Headquarters: Hamamatsu, Japan | Focus: Hardware | Est. 1953

Hamamatsu Photonics manufactures photonic devices and optical sensors for quantum technologies, including photomultiplier tubes (PMTs), single-photon avalanche diodes (SPADs) and qCMOS cameras used in trapped-ion and neutral-atom quantum computing. Recent products include the ORCA-Quest 2 qCMOS camera with faster readout and enhanced UV sensitivity, plus the company’s first commercial optically pumped magnetometer (OPM) for ultra-low magnetic-field detection in quantum sensing. Hamamatsu acquired NKT Photonics in 2022 to strengthen its quantum photonics capabilities.

Application areas listed are quantum computing, quantum sensing and materials science.

Hamamatsu Photonics is important because virtually every optical and photonic quantum architecture—whether trapped-ion, neutral-atom or photonic—depends on high-performance single-photon detectors, cameras and sensors. The company supplies core enabling components across multiple qubit modalities.

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10) Jij Inc.

Company link: https://quantumnews.in/company/jij-inc Quantum Score: 30 | Headquarters: Tokyo, Japan | Focus: Software | Est. 2018

Jij Inc. is a Japanese quantum computing company focused on quantum annealing. It develops the open-source software OpenJij for solving Ising Model and QUBO (Quadratic Unconstrained Binary Optimization) problems, and provides quantum annealing algorithms and tools that help enterprises apply quantum optimization to logistics, scheduling, and combinatorial optimization. The company connects academic quantum annealing research with practical industrial use in the Japanese market.

Through 2025, Jij continued to develop its quantum software platform and developer tools, with a focus on improving algorithm efficiency and expanding use cases. Engagement with the quantum developer community drives much of its product direction.

Jij Inc. is important because it bridges academic quantum annealing research and real-world industrial applications. Its open-source OpenJij library and optimization tools make quantum annealing more accessible for logistics, finance and combinatorial problems — key strengths of Japan’s industrial base.

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Closing Perspective

The top 10 Japanese companies ranked by QuantumNews illustrate an ecosystem that is simultaneously advancing large-scale superconducting processors (Fujitsu), application software for chemistry and optimization (QunaSys, Fixstars Amplify, Blueqat, Jij Inc.), and the critical materials and photonic infrastructure (Faraday Factory Japan, Fuji Electric, Fujikura, Hamamatsu Photonics, Anritsu) needed to make those systems practical. Japan’s quantum strength is therefore industrial as well as scientific: it combines national research partnerships, manufacturing scale and growing commercial software layers.

The bigger picture

Japan ranks #7 of 52 countries globally on QuantumNews' ecosystem rankings, with 52 quantum companies split across hardware (33) and software (19) focus areas. What stands out in this Top 10 is how Japan's quantum strength isn't concentrated purely in dedicated quantum startups — legacy industrial giants (Fujitsu, Anritsu, Fuji Electric, Fujikura, Hamamatsu Photonics) sit alongside newer software-native and hardware-native startups (QunaSys, Blueqat, Fixstars Amplify, Faraday Factory Japan) and a fresh national public-private hardware initiative (IMS Quantum Startup). That mix of century-old manufacturing depth plus focused quantum-native execution is a big part of what makes Japan's ecosystem distinctive.

Explore the full 52-company Japan ecosystem: https://quantumnews.in/companies/country/japan