Adaptive Cooling Support
Our goal is to provide additional cooling during normal operations and emergencies. The cooling capability has not yet been validated.
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COOLING TECHNOLOGY RESEARCH / 01
Pushing the limits of cooling
through technology.
Advancing the future of cooling—from Earth to space.
IceGuard™ is a cooling system under research and development.
We aim to support AI data center operations during emergencies and periods of peak demand.
MISSIONEmergency / Peak Demand
PHASEBasic Design / Demonstration Preparation
Area of UseEARTH / SPACE
CONCEPT IMAGE / RESEARCH AND DESIGN STAGE
PROJECT STATUSACTIVE DEVELOPMENT
01 AI DATA CENTER02 Emergency Cooling Support03 OUTER SPACE / PATENT APPLICATION NOT YET FILED04 Long-Term Goals
OUR CONCEPT
Don’t let heat stop
AI innovation.
As heat loads in AI data centers continue to rise, additional cooling capacity that does not rely solely on primary cooling equipment will become increasingly important.
IceGuard™ is being developed to support cooling during periods of high demand, power outages, and equipment abnormalities. The system uses a heat-management method developed by our company. To protect our intellectual property, we limit the technical information we make public. The project aims to verify performance and safety through a small cooling prototype.
Site-Adaptable Design
We are exploring a system that can be configured around each facility’s equipment and operating requirements.
Enhanced Resilience
Creating an additional option for unexpected heat loads and emergency conditions.
DEVELOPMENT PROGRESS
IceGuard™
Development Progress
From concept to demonstration. We disclose, to the extent possible, progress across intellectual property, external collaboration, engineering design, demonstration preparation, space-related research, and funding.
LAST UPDATED2026.10.04
Publicly disclosable development information will be updated as appropriate.
0%Concept and Preparation Stage
Current Progress
Development Complete100%
Patent Registration Progress
We received approval of the patent application. Patent registration is not yet complete.
We published this status on September 3, 2026. Payment of patent fees and registration procedures are the next steps.
Discussions with Universities
Discussions on possible technical evaluation and collaboration
Discussions are at an early stage toward establishing an evaluation framework.
Engineering Design
Detailed specifications being refined
We are refining the detailed specifications in preparation for building the small cooling prototype.
Small Cooling Prototype
Discussions in progress
The cooling prototype has not yet been built. We plan to build this prototype after the design is finalized.
Development Financing
Seeking financing for development
We are seeking funding to build the prototype and test its performance.
Space Data Center
Cooling System
Patent application not yet filed; initial research
A preliminary study is under way for a cooling concept intended for possible use in space environments.
Progress percentages are indicative figures based on the Company’s internal milestones. They do not represent verified product performance, safety assurance, or third-party certification.
EVIDENCE & VALIDATION
Demonstration & Evaluation Data
Turning a concept into measurable performance. The small cooling prototype has not yet been built. Once testing begins, objective measurements and independent evaluations will be published to the extent possible.
CURRENT PHASEDemonstration Preparation
Cooling Capacity and Temperature
Cooling capacity and temperature trends will be published together with the finalized test conditions.
Cooling Continuity
Operating duration and recovery behavior will be published together with the measurement method.
Power Consumption
Measured operating power consumption will be published with the applicable comparison conditions.
Safety & Operational Stability
Findings concerning abnormal conditions and operational stability will be published where possible.
Independent Evaluation
The evaluator, evaluation method, date, and publicly disclosable findings will be identified.
Testing in an Operating Environment
Test conditions, scope, and results from an operating environment will be published in stages.
Information Published with Each Result
- Test Conditions
- Measurement Method & Equipment
- Date
- Tester or Evaluator
- Results
- Limitations & Assumptions
“Not yet measured” and “not yet evaluated” do not mean zero performance. They indicate that objective measurement or evaluation has not yet been completed. Targets and forecasts will be clearly distinguished from measured results.
Potential Uses
From Normal Operations to Emergencies.Our Goal: Additional Cooling Capacity.
Peak-Demand Support
We are studying how additional cooling could help data centers operate during periods of high demand.
Power Outages and Equipment Abnormalities
Step-by-step verification is planned to evaluate its potential to support continued cooling during emergencies.
Integration with Existing Environments
Compatibility is being evaluated based on the conditions of individual data centers.
Cooling Research for Data Centers in Outer Space
Space Data Centers.
Cooling-system research for future applications.
We are studying a cooling concept for data centers that might operate in outer space. We are also preparing for a possible patent application.
Early research considers cooling and heat dissipation under thermal and operating conditions in outer space. These conditions differ from conditions on Earth. We are also studying how cooling could continue if part of the system fails. Technical details are not publicly disclosed in order to protect intellectual property.
PATENT STATUSCooling technology for data centers in outer space: Patent application not yet filed
Patent Application Not Yet Filed / Technical Details Are Not PublicBEYOND DATA CENTERS
Exploring cooling applications
in fields where exceptional reliability is required.
Over the long term, and only after rigorous safety and reliability testing, independent evaluation, and compliance with applicable laws and regulations, we intend to study potential applications in critical infrastructure.
One potential research topic is the possible use of the technology as supplementary cooling for the pools that hold spent nuclear fuel at nuclear power facilities. This remains a long-term research concept, and its suitability, performance, and safety for nuclear applications have not been evaluated. It is not intended to replace existing safety systems. Any future application would require compliance with applicable laws and regulatory requirements, as well as review, licensing, and other approvals by the relevant authorities.
01Prototype Testing02Rigorous Safety Testing03Independent Evaluation & Regulatory Compliance04Feasibility of Future Uses
NEXT MILESTONES
Four steps toward
practical implementation.
- 01NEXT
Finalize Demonstration Specifications
Define the scope of verification and evaluation conditions, and finalize the demonstration specifications.
- 02PLANNED
Build the Demonstration Unit
Build a small cooling prototype and establish an environment for safe testing.
- 03PLANNED
Cooling Performance and Safety Testing
Measure cooling capacity, duration, power consumption, and safety.
- 04PLANNED
Independent Evaluation and PoC
Based on external evaluation, pursue a phased proof of concept in an operating environment.
CORPORATE GOVERNANCE
Building a trusted foundation
for sustainable growth.
Rissel Inc. is progressively developing a governance framework appropriate to the Company’s scale and stage of growth, while considering a future stock exchange listing as one possible long-term objective. We seek to enhance corporate value sustainably and earn the trust of our stakeholders.
Internal Governance Systems Being DevelopedProgressive Development
Decision-Making & Accountability
We aim to support important business decisions through appropriate information sharing among company directors, with clear decision-making processes and accountability.
Financial & Cash Management
We will develop processes for continuous monitoring of budgets, performance, and cash flow to support sound accounting and management decisions.
Related-Party Transactions & Conflicts of Interest
We will develop procedures to assess the necessity, fairness, and potential impact of transactions involving directors, major shareholders, and other related parties.
IP & Information Management
We treat technical information before a patent application is filed, trade secrets, and personal data as important assets and will develop appropriate rules for access, storage, and disclosure.
Risk Management & Compliance
We will progressively identify business, technical, safety, legal, and information-security risks and develop internal rules and response procedures.
Transparent Disclosure
We will continue to communicate R&D progress, financial information, and important business information accurately and fairly, within the scope permitted for public disclosure.
This section includes current initiatives and future development priorities. It does not indicate that all related governance systems, policies, or procedures have been completed. Rissel Inc. is not listed on a stock exchange. A stock exchange listing remains one possible long-term objective; it does not indicate that a listing application or review has commenced or been approved, and no timing or completion is assured.
INVESTOR RELATIONS
Investor Relations
Communicating R&D and business progress with transparency.
We publish information on the development of our cooling technology, intellectual property, commercialization initiatives and management policy, within the scope permitted for public disclosure.
Inquiries Regarding Funding and Business PartnershipsLATEST DISCLOSURELatest Updates
- Intellectual PropertyNotice of Receipt of a Decision to Grant a Patent for AI Data Center Cooling Technology
As disclosed on September 3, 2026: we received a written decision from the Japan Patent Office approving the patent application. The patent had not yet been entered in the official patent register. Patent rights only take effect after the patent is entered in this register. The first small cooling prototype had not yet been built. The financial impact was undetermined.
- R&DNotice Regarding the Progress of Discussions with Nakazono Kiko Co., Ltd. Toward Cooperation in Manufacturing the IceGuard™ Small Cooling Prototype
As disclosed on August 19, 2026: a non-disclosure agreement had been signed with Nakazono Kiko Co., Ltd. No final manufacturing or joint-development agreement had been signed. Cooperation terms remained under discussion. This disclosure did not confirm any revenue or profit; the financial impact was undetermined.
- ManagementGovernance Development Policy Published
- Financial ResultsFinancial Year 2025 Financial Highlights Released
- CorporateIceGuard™ Official Website Launched
- R&DIceGuard™ Development Progress Published
- R&DInformation Published on Space Data Center Cooling Research and Patent Application Preparation
- ManagementLong-Term Growth Policy, Including a Potential Future Stock Exchange Listing, Published
Rissel Inc. is not listed on a stock exchange. This page is provided solely to enhance understanding of the Company and does not constitute an offer or solicitation to acquire shares or other securities. Forward-looking statements reflect plans and expectations as of the date of publication and are not guarantees of future results.
FINANCIAL RESULTS / FY2025
Financial Year 2025 — Financial Highlights
REPORTING PERIOD2024.11.01 — 2025.10.31Comparative period: Financial Year 2024 2023.11.01 — 2024.10.31
Financial year 2025 compared with financial year 2024:
Sales revenue decreased by 7.8%.
Operating profit increased by 55.8%.
Ordinary profit increased by 177.1%.
Net profit decreased by 53.5%.
- Sales Revenue
- 4,250.1JPY 10,000 YoY −7.8%
- Operating Profit
- 36.5JPY 10,000 YoY +55.8%
- Net Assets
- 516.1JPY 10,000 YoY +24.1%
- Equity Ratio
- 32.0% 27.1% → 32.0%
OUTLOOK Sales revenue for financial year 2025 decreased 7.8% year on year. The sales revenue forecast for financial year 2026 is approximately 31.8% higher than the sales revenue for financial year 2025.
Sales revenue forecast for financial year 2026 (approximate)JPY 56,000,000
The financial year 2026 figure is an internal estimate as of August 2026 and is not an actual result. It may vary depending on business conditions and other factors, and achievement is not guaranteed.
¥0Monetary Amount (JPY)
Confirmed Customer Orders Awaiting FulfilmentAs of Included: confirmed customer orders awaiting fulfilment.Excluded: projects under discussion.
KEY FINANCIAL METRICS
Key Financial Metrics
Changes in Key Balances
Measurement unit: JPY 10,00032.0%Equity Ratio
27.1% → 32.0%Increase from the prior periodLiquidity Ratio (Current Assets / Current Liabilities) 53.7% → 107.7%
IncreaseOperating Profit +55.8%Operating profit exceeded the prior period.
DecreaseRevenue −7.8%Revenue was below the prior period.
IncreaseLiquidity Ratio (Current Assets / Current Liabilities) +54.0ptIncreased from 53.7% to 107.7%.
ReviewBorrowings +26.8%Funding use and repayment planning are being managed.
Financial Amounts
Currency: Japanese yen (JPY)| Item | Financial Year 2024 | Financial Year 2025 | Change |
|---|---|---|---|
| Sales Revenue | 46,111,163 | 42,500,788 | −7.8% |
| Operating Profit | 234,045 | 364,558 | +55.8% |
| Ordinary Profit | 146,696 | 406,453 | +177.1% |
| Net Profit | 2,157,881 | 1,003,353 | −53.5% |
| Net Assets | 4,157,881 | 5,161,234 | +24.1% |
COMPANY PROFILE
RisselInc.
Working toward the practical deployment of cooling technology.
IceGuard™ is our core R&D project. We are working toward the practical deployment of cooling systems for AI data centers. The Company also operates カークリニックス (new and pre-owned vehicle sales), 湧米 (rice sales), and 湧米キッチン (food-service operations), building businesses rooted in the local community. Beginning with terrestrial demonstration work, the Company is also exploring long-term fields such as space data center cooling.
- Company Name
- Rissel Inc.
- Company Representative
- Representative Director and PresidentChikakazu Yoshida
- Company Directors
- Executive Vice President of the Company; Company Director瀬尾 隆志
- Director, Finance桑畑 昭彦
- Company Founding Date
- Address
- 1F, 3-12-9 Kokubu Chuo
Kirishima, Kagoshima 899-4332, Japan - Phone / Fax
- TEL+81-995-56-5355FAX+81-995-56-5356MOBILE+81-90-8766-5039
- Website
- https://rissel.jp/en/
- Project
- IceGuard™
- Business Activities
- IceGuard™R&D of cooling systems for AI data centers
- カークリニックスSales of new and pre-owned vehicles
- 湧米Rice sales
- 湧米キッチンFood-service operations
- Research Fields
- Emergency and peak-demand cooling / Space data center cooling concepts
- Contact Us
- Go to Contact Form
MESSAGE FROM OUR COMPANY PRESIDENT
Our starting point lies in
the fundamentals
of physics.
I have always valued returning to the fundamentals of physics and applying that perspective to new ideas.
As AI advances rapidly, I believe that heat generated in data centers will become an increasingly significant challenge. This led me to ask whether a different cooling option could be conceived by starting again from the fundamentals of physics. That question became the starting point for the research and development of IceGuard™.
We are preparing to build a cooling prototype. We plan to evaluate performance, safety and practical viability step by step. Our first priority is to validate its potential as a cooling technology for terrestrial AI data centers. Beyond that, as a long-term research theme, we are also conducting preliminary studies into cooling possibilities that could support data use in space environments.
From concept to technology.
From technology to society.
Together with companies, research institutions, and engineers, we will continue working to develop this initiative into a cooling technology that can serve society.
Rissel Inc.
Representative Director and President
OUR PRINCIPLES
Our Six
Principles
The name Rissel is derived from the initials of six guiding principles.
Respect
Valuing our customers, business partners, and employees.
Integrity
Acting with honesty and integrity.
Sustainability
Building businesses with consideration for the environment and society.
Strength
Developing an organization capable of responding flexibly to challenges.
Excellence
Pursuing the highest standards of quality and service.
Leadership
Growing as a leader in our industry and community.
BUILD THE NEXT STANDARD
This technology should not remain only a concept.
We are seeking partners to help us develop, test and commercialize our cooling technology. We welcome support through technology, facilities, funding or expertise.
Support This Challenge ↓CONTACT FORM / 01
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