Location: Shinjuku-ku, Tokyo
Employees: 163
Established: October 1, 1931 (originally founded as part of Obayashi in 1895)
President: Masato Yanou

We were founded as a sawmill for Obayashi Store, the forerunner to today’s Obayashi Corporation, in Osaka in 1895. From the very earliest years, we were involved in constructing Tokyo Central Station (today’s Tokyo Station)VIP Lounge, Osaka Shochikuza Theatre, Kabukiza Theatre, Takarazuka Hotel, and other landmarks. Early in the Showa Era (starting in 1926), we outfitted the Buenos Aires Maru and Argentina Maru passenger ships and did interior work on the observation car of the South Manchuria Railway’s Asia Express, known as a super-express train at the time. We built a new Tokyo factory in 1948 to step up production in the Tokyo metropolitan region. After the factory’s subsequent move to Saitama Prefecture, we began working actively on product development, including interior building materials. In 1993, we changed our company name from NAIGAI MOKUZAI KOGYO to Naigai Technos, which remains our name today. Later, when we started taking outsourcing orders from Obayashi’s procurement department, we opened a trading department to handle construction materials and other products. In 2002, we moved our head office function from Osaka to the Fujimino Plant; the Main Plant in Saitama.

Over our long history, we have finished a long list of projects through our involvement in construction using wood to maximize design appeal. We have received particularly high acclaim for the interiors of concert halls, for which we have a track record of construction all over Japan.

Tokyo Central Station (today’s Tokyo Station) VIP Lounge as it
appeared in March 1914

In 2017, we became the first wood construction company to earn FSC® CoC certification* and PEFC CoC certification,*two international forest certification programs. At the Main Plant, we have a strict control system to ensure that certified wood does not mix with non-certified wood. That boosts our product value and helps differentiate us from other

Processing wood at the Main Plant

*CoC (Chain of Custody) certification: Certification that forest products produced in certified forests have been properly processed and distributed.

Using Independent Procurement and Development Expertise to Contribute to Society and People

Our trading department handles a wide range of products, from major construction materials like wet concrete and rebar needed at construction sites to heavy construction machinery like shield machines and boring machines for tunnel excavation.

We also develop labor saving construction methods to shorten construction periods and save costs. Working with the Obayashi Technology Research Institute, we developed AlphaTimber™, a new noncombustible wood product. We are now endeavoring to step up sales of products like these.

New noncombustible wood product AlphaTimber™. The wood is made noncombustible by covering its surface with a decorative layer less than 0.5 mm thick that includes decorative natural wood veneer, multi-layer aluminum foil sheets, and coating.

In Use at the Obayashi Group

We are working with Obayashi to promote the use of wood, a material that has started to capture the public’s attention. We are participating in a project now underway to construct an all-timber high-rise fire-resistant building. With all structural components made of wood, the building will serve as a training facility for the Obayashi Group.

A next-generation training facility for the sustainable growth of the
Obayashi Group

Powered by Technology and Expertise We Have Gained Since Our Founding

Having marked 125 years in business last year, we have earned a strong reputation for the technology and expertise we have acquired since our founding. For that reason, we are winning orders from other general contractors besides Obayashi, as well as directly from business operators. Such projects include preservation and restoration of the Tokyo Station Marunouchi Building as well as work on the Ginza Kabukiza Theatre, the FUJIYA HOTEL in Hakone, and THE HIRAMATSU Kyoto. We are endeavoring to step up marketing as we aim to expand our business further.

(completed 2016)

FUJIYA HOTEL (completed 2020)

THE HIRAMATSU Kyoto (completed 2020)
Rebuilding of the Head Office Plant is expected to be complete in
June 2023.
(Photo: Akiyoshi Fukuzawa)

We are also expanding and strengthening our workforce to build up our business in Western Japan. We will work on projects related to Expo 2025 and the redevelopment of the
Tenjin area of Fukuoka.

In addition, we are rebuilding our Main Plant in Saitama Prefecture to further enhance our production capacity. As a leader in wood construction, our aim is to use this facility to pass down our technology to future generations and build wood spaces.

Rebuilding of the Head Office Plant is expected to be complete in
June 2023.