Number Group Inc, Progress of the "Natural Toilet" Project and Introduction of "Technical and Construction Support Companies

2025.07.31 16:00

ナンバーグループ株式会社

Number Group Inc. (headquartered in Izunokuni City, Shizuoka Prefecture) is developing a "natural toilet," a flush toilet system that can be used in times of disaster. This development project aims to prevent disaster-related deaths by solving the toilet problem in the event of disasters such as power outages, water cutoffs, and sewerage system outages. We are pleased to announce the progress of the project and the "technology and construction support companies".

災害時も使える「天然トイレ」プロジェクト

Natural Toilet" Project for use during disasters

Background of Development

Do you know the reality that "toilets" can kill people?

In the event of a disaster, the first thing to go wrong is the toilet.

In many cases, holding up defecation can lead to a life-threatening situation.

If there were toilets that could be used as usual, it would save lives and reduce anxiety and stress.

Children would laugh and say, "It's bright and safe," and the elderly would be able to use it without difficulty.

Such a "place of peace of mind" is right next door.

That is the "natural toilet" we are developing.

Our company's starting point is "to protect human life.

Kiuchi, who lives in Izunokuni City, Shizuoka Prefecture, faces the risk of a Nankai Trough earthquake, which is estimated to have a 70-80% probability of occurring within 30 years.

He challenged himself to "build a completely self-sufficient house" when he was working for a trading company.

With that aspiration in mind again, I started my own company with the hope of reducing disaster-related deaths.

Having never experienced a disaster, I researched thoroughly.

Great Hanshin-Awaji Earthquake: 1.3 million houses were without water and toilets could not be used.

Kumamoto Earthquake: Some people lost their lives because they had to hold on to their toilets

Before food, excrement takes lives.

We want more people to know this fact.

Technical and construction support companies

This project will receive technical and construction support from the following companies, from Hokkaido to Kyushu and Okinawa, to ensure that post-construction maintenance is simple and of the same standard. We will consolidate the top-level "technological" and "corporate" capabilities in each functional field.

Toilet building

RC Core Co.

Based on the know-how of "BESS," the largest log house manufacturer in Japan, R.C.CORE is in charge of designs that make the best use of natural materials.

BESS" is a company that proposes "enjoyment" rather than "living" through the provision of unique homes that utilize natural materials. BESS" is a company that proposes "enjoyment" rather than "living" through the provision of unique homes that utilize natural materials.

Mayo Construction Co.

Responsible for container house style design. Providing meticulous service and advanced construction techniques mainly in the Chushin region of Nagano Prefecture, the company is also actively involved in the SDGs and proposes the use of natural energy and energy-efficient housing. For this project, we propose buildings that can be installed quickly.

[Well System

Nisaku Corporation

Responsible for well drilling and groundwater utilization.

A specialized company that has been dealing with "water" and "earth" for over 100 years.

We are the first company in Japan to drill full-scale deep wells, and are particularly strong in groundwater investigation and utilization technology and maintenance to extend the service life of wells, thereby contributing to society while protecting local water resources.

[Water supply system

Daigaku Sangyo Co.

Responsible for providing water treatment systems that ensure safe and reliable water quality.

Over the years, we have contributed to society in the fields of "water treatment" and "disaster prevention. In particular, we have earned a reputation as a water treatment professional that handles everything from design to maintenance for all types of water treatment plants, from tap water and simple water supply systems to industrial and household water treatment systems.

[Piping

Techno Flex Co.

Responsible for providing highly earthquake-resistant flexible hoses and piping joints. Flexible tubing that absorbs displacement and vibration of piping during earthquakes and minimizes damage protects critical lifelines. They can also cope with extreme temperature changes and support the stable operation of facilities during emergency response and restoration work in the event of a disaster.

Septic Tank (Drainage)

Fuji Clean Industry Co.

A water treatment manufacturer that boasts the top share of the domestic market for its high-performance, compact, combined treatment septic tanks. The company promotes technological development and quality improvement under the theme of "protecting beautiful water. The company also provides after-sales support through a nationwide maintenance system.

Electrical System

VARIOSTAR Corporation

Provides power supply systems that combine renewable energy sources such as solar power generation with energy storage technology. Through "optimal control of power generation and storage," the company aims to realize a self-sufficient energy society. We contribute to the construction of a robust social infrastructure that can ensure power supply even in times of disaster.

Facility Construction

USEN Techno Service Corporation

A group company of U-NEXT HOLDINGS, USEN TECHNO SERVICE CORPORATION provides telecommunications, electrical, construction, and demolition work for stores, offices, commercial facilities, and other facilities.

In cooperation with more than 400 subcontractors nationwide, the company performs tens of thousands of construction projects per year.

The company handles a wide range of telecommunications and electrical work, focusing on installation and maintenance of store DX and IoT terminals.

■Professor Takamura's Advice

Professor Hidenori Takamura of the Department of Architecture, Faculty of Engineering, Shinshu University, has provided us with expert advice in the field of building environment and facilities engineering. In particular, he has given us valuable advice on design aspects such as improving energy efficiency and optimizing insulation performance.

By taking advantage of Professor Takamura's knowledge, we aim to realize a "natural toilet" system that is both comfortable and sustainable, even in times of disaster.

高村教授

Professor Takamura

■Future Prospects

Number Group Inc. has now started specific discussions for commercialization of the "Natural Toilet" in cooperation with "technical and construction support companies.

We will gather knowledge and technology from companies and experts in each function to create a model of how a "natural toilet system that can be used even in times of disaster" can function using only natural energy. We aim to make this "modeled flush toilet system (natural toilet)" a "guideline or recommendation" from the "national government" and "organizations and companies related to toilets". We believe that the adoption of this system by local governments and companies throughout Japan will not only reduce CO2 emissions, but will also help to realize a strong national land infrastructure. We believe that this project will lead to "environmental preservation" and "lifesaving. In the future, we would like to contribute to the creation of a safe environment for local residents and improve the disaster preparedness of the entire community by promoting the permanent installation of the system in public facilities, evacuation centers, and disaster response centers. We will continue to work together with local governments, companies, and experts to realize new infrastructures that protect lives and peace of mind. Number Group Inc. will continue its innovative efforts to solve the problem of toilets in times of disaster. We look forward to your continued support and cooperation.

■About Number Group Inc.

Believing that our efforts would be half-hearted in our position as a company employee, we came to the choice of becoming "independent" and established Izu Number Godo Kaisha on March 15, 2024. Subsequently, as of March 10, 2025, the company name was changed to "Number Group, Inc.

The "purpose" of establishing the company is to develop and popularize a "flush toilet system that can be used during disasters.

We believe that the realization of this "objective" will minimize the number of "toilet-related disaster-related deaths" that occur after a disaster.

代表取締役　木内剛