What Tomoe does

Tomoe Corporation (巴コーポレーション) is a Japanese construction and steel-fabrication company founded in 1917 in Tokyo and listed on the Tokyo Stock Exchange, operating in its 94th fiscal year (FY2025). The company specializes in four interlocking lines: proprietary spatial/skeletal structures (Diamond Truss since 1932, Tomoe Uni-Truss since 1982, H-Diamond Shell, Tomoe Timber Joint), transmission and communication towers, anechoic chambers and electromagnetic shielding, and steel bridges, alongside general construction of schools, public facilities, logistics centers, and seismic retrofitting. Core technology rests on government-certified proprietary structural systems, vertically integrated design-fabricate-construct capability across three domestic factories (Oyama S-grade MLIT 30,000 tons/year; Sapporo H-grade 15,000 t/yr; Towada H-grade 8,000 t/yr; combined ≈53,000 t/yr) and an in-house R&D center (Ishido Innovation Center) with full-scale tower testing and wind tunnel.

The company makes money primarily through project-based construction contracts with government agencies and large enterprises. Pricing is project-specific and not publicly disclosed; revenue is recognized per construction contract, with one-off steel-structure fabrication projects and ancillary real-estate services completing the mix. Go-to-market is direct enterprise and public-sector field sales through four product-aligned sales divisions (construction, steel structures, bridges, towers) supported by ten regional branch offices across Japan (Sapporo, Tohoku, Utsunomiya, Tokyo, Nagoya, Osaka, Kyushu, plus two operations-support offices). Customer base spans public-works and government procurement (MLIT, JR, Boards of Education, prefectures and municipalities, Ministry of Defense) and large enterprises (TDK Corporation, Tobu Railway, East Japan Railway, Yamato Transport, FANUC, Tokyo Electric Power Grid, Maeda Construction). Long-term technical partnerships anchor revenue, most notably the 45+ year TDK relationship for anechoic chambers (300+ installations; Tomoe designated as TDK's specified construction company since FY2013) and joint development with Kawasaki Heavy Industries on KT-Slab composite floor decks (NETIS R4-0471). Notable project credentials include steel fabrication of approximately 9,000 tons for Tokyo Skytree (634m).

Name

Tomoe

Legal name

巴コーポレーション

Website

https://tomoe-corporation.co.jp

Company type

Public

Founded year

1917

Operating status

Operating

Headcount range

251–500 employees

Short description

Tomoe Corporation is a 107-year-old Japanese construction and steel-fabrication firm specializing in proprietary spatial structures, transmission towers, anechoic chambers, bridges, and general construction for government agencies and large enterprises across Japan.

Ownership category

akta.pro rank

Product category

Structural Steel Construction

NAICS

Plate Work Manufacturing (332313), Commercial and Institutional Building Construction (236220)

SIC

Fabricated Structural Metal Products (3440)

akta.pro primary industry

Steel Plate, Sections & Welded Assemblies (IMADACAD)

akta.pro secondary industries

Office & Corporate Building Construction (IMAFACAA), Telecom Tower & Mast Construction (Greenfield Builds, Foundations, Erection) (IMAFAIAC), Warehousing, Distribution & Cold Storage Facility Construction (IMAFADAL)

Keywords

• Steel structure construction
• Spatial structure fabrication
• Transmission tower manufacturing
• Electromagnetic shielded chambers
• Steel bridge construction

Headquarters

HQ city

Tokyo

HQ country

Japan

HQ region

Asia

Offices14 records

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Supply Chain, Operations, Technology or R&D, Infrastructure, Marketing or Sales

Revenue model

1. Construction contracts: General construction services including building construction, spatial structures, bridges, transmission towers, and specialized anechoic chamber/electromagnetic shielding facilities. Revenue is generated through direct contracts with public and private sector clients. Projects range from school buildings to large-scale infrastructure like Tokyo Skytree. This is the primary revenue stream.
2. Steel structure manufacturing and fabrication: Design, fabrication, and supply of steel structures including special steel structures, transmission towers, and space frame components. Manufacturing is done at three domestic factories (Oyama, Towada, Sapporo) with a combined annual processing capacity of 53,000 tons of steel.
3. Real estate: Real estate services related to construction projects.

Go-to-market motion1 record

Distribution channels2 records

Marketing channels7 records

Core offering

Tomoe Corporation is a Japanese construction and steel structure fabrication company specializing in proprietary spatial structure systems (Diamond Truss, Tomoe Uni-Truss, H-Diamond Shell), steel transmission towers, steel bridges, and electromagnetic shielded/anechoic chambers. The company operates three domestic steel fabrication factories (Oyama, Sapporo, Towada) with combined annual processing capacity exceeding 53,000 tons and serves public sector agencies and large enterprise clients through ten regional branch offices across Japan.

Product overview

Tomoe Corporation is a comprehensive construction and steel manufacturing company offering a portfolio of space structure systems (Diamond Truss, Tomoe Uni Truss, H Diamond Shell/Truss, S Diagonal Truss, Tension Structures), seismic support systems (Anti-seismic Support), and hybrid solutions (Tomoe Timber Joint). Core offerings also include anechoic chambers/electromagnetic shielding, steel towers, steel structures, general construction, composite floor decks (KT-Slab), and bridges. The company operates three manufacturing plants (oyama, Sapporo, Towada) certified to ISO 9001 and ISO 14001 with Ministry of Land certification grades S and H.

Differentiator

Problem solved

Functional benefit

Brands

• ダイヤモンドトラス (Diamond Truss): Three-dimensional spatial structure system using diagonal steel members for large column-free spaces, developed in 1932
• トモエユニトラス (Tomoe Uni-Truss)
• Hダイヤモンドシェル (H Diamond Shell)
• SGめっき®
• KT-スラブ (KT-Slab)
• トモエベース (Tomoe Base)
• SWORD工法 (SWORD Method)
• トモエティンバージョイント (Tomoe Timber Joint)

Products and services

• Diamond Truss (ダイヤモンドトラス) Three-dimensional spatial structure system using angle steel members arranged in triangular and diamond mesh patterns on curved surfaces, enabling large column-free spaces for sports facilities, schools, warehouses, and hangars.
• Tomoe Uni-Truss (TUT) System Truss (巴ユニトラス) Space frame system using steel tubes (P48-P457 sizes), steel balls at joints, and high-tension bolts, certified by the Ministry of Land, Infrastructure, Transport and Tourism in 1982. Enables free-form curved spatial structures.
• Tomoe Uni-Truss Single (巴ユニトラス・シングル) First domestic single-layer system truss with successful moment transfer at ball joints, enabling light-filled spaces with membrane or glass finishing materials on single-layer lattice shell structures.
• H-Diamond Shell (H形鋼による単層シェル) Single-layer lattice shell structure using H-shaped steel members with torsion absorption at node connections, enabling simplified and standardized joints and free-form roof surfaces.
• S-Diagonal Truss (Sダイアゴナルトラス) Space truss using angle steel for upper chords and steel tubes for lower chords and lattice members, featuring S/D type (upper orthogonal + lower diagonal) and D/S type mesh patterns with conventional steel plate and high-strength bolt connections.
• Tension Structures (テンション構造) Tension structures using tension-specific members including section steel, rods, and cables. Includes tension chord structures, radial bidirectional tension chord structures, suspended roof structures, and tension lattice truss domes.
• Tomoe Timber Joint (巴ティンバージョイント) Steel-to-timber joinery system for wooden single-layer shells where steel parts yield first to protect wood from brittle damage, ensuring deformability of the entire building with adjustable parts for various grid and triangular mesh shapes.
• Anechoic Chambers and Electromagnetic Shielding (電波暗室・電磁シールド) Design, construction, and maintenance of EMC measurement chambers and electromagnetic shielded rooms for EMC testing, antenna measurement, and Tempest security applications, achieving 100dB+ shielding performance. Includes 10m method and 3m method anechoic chambers, building-integrated designs, and high-performance shielding.
• Steel Towers (鉄塔) Design, fabrication, construction, and maintenance of transmission towers (square, triangular, environmental harmonization types), communication towers, meteorological observation towers, and chimney support towers for power transmission (275kV+), microwave communication, and related applications.
• Steel Structure Fabrication (鉄骨・特殊鉄骨) Specialized steel frame structures for buildings manufactured at three domestic factories (Oyama: 30,000 t/year S-grade, Sapporo: 15,000 t/year H-grade, Towada: 8,000 t/year H-grade) with ISO 9001 and ISO 14001 certifications and government-certified fabrication grades.
• General Construction (総合建設) Comprehensive general construction services for educational facilities (schools, gymnasiums), public facilities, production and logistics facilities, seismic diagnosis and reinforcement for existing buildings, and real estate services.
• KT-Slab Composite Floor Deck (合成床版KTスラブ) Composite floor slab combining bottom steel plate and concrete with perforated T-rib shear connectors, jointly developed with Kawasaki Heavy Industries. Registered as NETIS new technology (R4-0471), achieving 75% weight reduction and 80% cost reduction compared to previous designs.
• Bridges (橋梁)

Quantifiable outcome

• Over 5,000 Diamond Truss structural installations completed since 1932
• +5 more outcomes

Named customers13 records

Segments5 records

Ideal customer profiles5 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature13 records

Partnerships

Four partnerships are on record, tiered minor and core.

• Reiwa Construction (令和建設株式会社)minorStrategic or Co-development Partner · 1 January 2024Equity acquisition and consolidation as a subsidiary in August 2024, with additional share acquisition in March 2024 resulting in consolidation. Extends Tomoe's construction capabilities.
• Kawasaki Heavy Industries (川崎重工株式会社)coreStrategic or Co-development Partner · 1 January 2012Joint development of the KT-Slab composite floor slab system. Leveraged Kawasaki's expertise in truss-type shear connector composite slabs. KT-Slab registered as NETIS new technology (R4-0471).
• TDK Corporation (TDK株式会社)coreStrategic or Co-development Partner · 1 January 1976Long-term strategic partnership for anechoic chamber development since 1976. From FY2013, Tomoe became the designated construction company for complete TDK EMC chamber projects directly contracted from TDK. Joint development of anechoic chamber technology including building-integrated designs, seismic-following shield methods, and high-performance shielding doors. Over 300 installations completed together.
• Izumi Kousan (株式会社泉興産)minorOthersRelated company (集团公司). Located at Tokyo headquarters address. Real estate and related services.

Scale indicators6 records

Recent moves6 records

Expansion highlights5 records

Direct peers

• Komai Haltec Co., Ltd. (株式会社駒井ハルテック): Komai Haltec is a Japanese steel fabrication and bridge construction company. Both Tomoe and Komai Haltec compete directly in the Japanese steel bridge and structure market serving government and infrastructure clients with vertically integrated design, fabrication, and construction capabilities of comparable mid-cap scale.
• Kawada Industries, Inc. (川田工業株式会社): Kawada Industries is a Japanese steel bridge and structure fabricator with civil engineering focus. Both companies compete for Japanese government bridge, infrastructure, and steel structure projects with similar vertically integrated business models and customer base.
• Yahagi Construction Co., Ltd. (矢作建設工業株式会社): Yahagi Construction is a Japanese general construction company with significant steel structure building work. Both companies compete in the Japanese commercial and industrial steel structure construction market with vertically integrated capabilities and similar mid-cap scale.
• Nippon Steel Tower Industry Co., Ltd. (日本鉄塔工業株式会社): Nippon Steel Tower Industry specializes in steel transmission and communication tower design, fabrication, and construction. The two companies are the most direct competitors in Japan's power transmission and telecom tower market serving electric utilities and telecom operators.
• Yokogawa Bridge Holdings Corp. (横河ブリッジホールディングス株式会社): Yokogawa Bridge is one of Japan's leading steel bridge construction specialists. Both Tomoe and Yokogawa Bridge are direct competitors in the Japanese steel bridge market serving public sector clients and infrastructure projects with comparable product offerings and end customers.

Broad incumbents

• Takenaka Corporation (株式会社竹中工務店): Takenaka is one of Japan's largest general construction companies. Both serve Japanese clients with steel building construction, though Takenaka operates at much larger scale (megaproject focus) and broader scope as a full-service general contractor that typically engages Tomoe as a steel structure subcontractor on large projects.
• Nippon Steel Engineering Co., Ltd. (日鉄エンジニアリング株式会社): Nippon Steel Engineering is one of Japan's largest steel structure and engineering companies. Both serve Japanese infrastructure clients with steel fabrication capabilities, though Nippon Steel Engineering operates at much larger scale with broader product portfolio and deeper integration with primary steelmaking.
• JFE Engineering Corporation (JFEエンジニアリング株式会社): JFE Engineering is a major Japanese engineering, steel structure, and plant construction company. Both compete in steel fabrication for infrastructure projects, but JFE Engineering operates at substantially larger scale with a broader portfolio including environmental plants and energy infrastructure.
• Obayashi Corporation (株式会社大林組): Obayashi is a top-tier Japanese general contractor with megaproject capabilities. Both companies participate in the Japanese construction market for steel building and infrastructure projects, with Obayashi operating at much larger scale and broader portfolio, often hiring Tomoe as steel structure subcontractor.
• Taisei Corporation (大成建設株式会社): Taisei is a top-tier Japanese general contractor. Both companies participate in the Japanese construction market with steel building capabilities, with Taisei operating at megaproject scale and broader full-service general contractor scope that typically engages Tomoe for specialty steel structure work.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat6 records

Key risks6 records

Key highlights7 records

Customer concentration

• YouTubeyoutube.com/channel/UCzVvGIojQKLHOj2SDU_D8_A/featured

Compliance2 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles1 record

Subsidiaries5 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A1 record

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Tomoe