the future.



material Sales


Ceiling System


over view

Yagi Kozai Co. Ltd., founded in 1963, has been offering wide-ranging service related to steels. We have been dealing with not only distributions of steels but also processing and contracted jobs of steel structures and reinforced concrete structures.
In Japan, as a precaution against earthquakes, there is a demand for construction techniques with high resistance to earthquakes, durability, and safety. Thus, a company with both reliable techniques and a solid business foundation is highly appreciated by manufacturers, trading companies and customers.
Also, in recent years, there is a call for deregulation and cost reduction. Against this backdrop, we will continue our efforts to expand the distribution channels and reduce costs, thereby answering the needs of customers.
We appreciate your continued support.

Our services



A long business record enables us to secure various steels.
We answer all sorts of needs quickly regardless of the size.

Yagi Kozai Co. Ltd. has its origin in sales of steels structures. Given our long experience, we are highly confident about sales of steel structures.
The steel business is in the age of diversity; demands are various including low price, high quality and handiness. Answering these demands requires a huge task of securing various steels.
Yagi Kozai Co. Ltd. owns company warehouses and has the know-how and networks nurtured through the long experience. This enables us massive buy-ins and both large and small quick supplies. Thus, ‘supplies according to the time and quantity of the customer’s choice’ has become possible.
Our business is highly appreciated by fabricators, general constructors, design offices and other business associates: they say ‘Yagi Kozai can supply anything’. This way, we support numbers of steel construction sites.

More detail (japaneese)



High-quality contracted jobs are founded on the mutual trust.
Our networks will realise customer’s ideals.

One of the pillars of Yagi Kozai Co. Ltd. is contracted jobs involving steel structures and reinforced concrete structures. Before a completion of a contracted job, various tasks need to be covered: securing materials, selecting fabricators, price setting, inspection for full-size drawing, and ensuring safety.
We ensure the quality of our contracted jobs by building networks with a first-class architect, first-class building operation and maintenance managers, and high-skilled constructors.
Not only do we secure materials as a professional steels company, we also introduce constructors suitable for each property and provide jobs for constructors as a part of our sales works.
Yagi Kozai Co. Ltd. works as an intermediary to bring benefits to both customers and constructors. Ours is a ‘mutually beneficial business’, the ideal form of contracted jobs.

More detail (japaneese)



The ceilings serve as a preventative measure against damages by the collapse.
INNSSOL SYSTEM gives excellent decorative and lighting effects.

Membrane ceilings are the next-generation ceilings using durable, light and flexible membranes. They can endure large shape-changings and strong impacts. Even in the unlikely event of collapse, they are credited to be highly safe due to their light weight. If installations above membrane ceilings drop, the ceilings can catch them. Membrane ceilings are extremely effective in an earthquake-prone country Japan while they also meet the needs of the modern age.

More detail (japaneese)


July 1, 1962
September 6, 1963
managing officers
Chairman Kota Yagi
President Yoshikazu Fukui
30 million yen
Number of employees
69 (52 men, 17 women)
Net sales
  • 16.9 billion yen (period ended January 2022)
  • 12.8 billion yen (period ended January 2021)
  • 12.6 billion yen (period ended January 2020)
Certified employees
  • First-Class Building Operation & Maintenance Engineer (8 employees)
  • Registered Real-Estate Broker (2 employees)
  • First-Class Special Steel Materials Sales Engineer (1 employee)
Business Activities
  1. 1. Sales of steel materials
  2. 2. General construction work, construction of steel structures, construction of steel-reinforced concrete
  3. 3. Interior finishing for membrane ceilings, optical membrane ceilings, etc.
  4. 4. Metal processing
  5. 5. Sales and brokerage for real estate
  6. 6. All business activities related to items listed above

greetings from the president


Our history dates back more than half a century. We were one step ahead of other steel trading companies in turning our eyes to the construction industry, the source of steel demands; we expanded our business from distributions, supplying of materials, to contracted jobs involving steel structures and reinforced concrete structures. We do business with various stakeholders through our contracted jobs while supplying materials to meet the demands of customers.
In recent years, in view of the increasingly complicated needs of customers and accelerating business speed, we opened a Tokyo brunch. We always look into the future and aim high.
Our challenging spirit has its origin in the management philosophy we have cherished since the foundation: to contribute to the social development through steel business. Today, steels are in demand in any industry; in the construction industry, they serve as the framework and are irreplaceable.
Yagi. Kozai. Co. Ltd. will continue its efforts to retain and develop the trust we have as a business partner and be as irreplaceable as steels are, contributing the development of society.



no limit

since 1962