What Aomi Construction does

Aomi Construction Co., Ltd. (あおみ建設株式会社) is a Tokyo-based Japanese marine civil engineering specialist founded in 1917, operating across port and harbor construction, ground improvement, airport construction on reclaimed land, seismic reinforcement, and water resources infrastructure. The company maintains a fleet of proprietary construction vessels and equipment — including the Kaikyo grab dredger, AFD-8000 floating dock, Big Crab underwater backhoe (7th generation, amphibious), and offshore SCP vessels — and holds multiple patents for specialized construction methods, notably the Re-Pier seismic reinforcement system, KS-EGG static sand compaction pile, S·MIX deep mixing, and the jointly-developed (with University of Tsukuba) Soko ni Iruka anti-multipath underwater acoustic positioning system.

Aomi generates the majority of its revenue through competitive public-works tenders with national and local government agencies (MLIT and its regional development bureaus, prefectural and municipal governments), supplemented by private-sector contracts for industrial clients such as Toyota Motor Corporation. The company operates a nationwide network of 12 branches and 6 sales offices covering all 11 Japanese regions, and has a limited overseas track record (Korea, China, Madagascar). The business model is one-time project-based construction contracting, with pricing set through public competitive bidding. In January 2026, Aomi Construction became a member of the Shimizu Corporation Group, and the company also holds two operating subsidiaries (Shinko Techno, Inoue Kogyo) and one joint venture (Shirasagi Farm in agriculture).

Name

Aomi Construction

Legal name

AOMI CONSTRUCTION CO.,LTD.

Website

https://aomi.co.jp

Company type

Private

Founded year

1917

Operating status

Operating

Headcount range

251–500 employees

Short description

Aomi Construction is a 100+ year-old Japanese marine civil engineering specialist (founded 1917) that builds ports, harbors, airports, and ground improvement projects for government and private clients using proprietary underwater construction vessels and patented methods.

Ownership category

akta.pro rank

Product category

Marine Civil Engineering

NAICS

Ship Building and Repairing (336611)

SIC

Ship & Boat Building & Repairing (3730), Heavy Construction Other Than Bldg Const - Contractors (1600)

akta.pro primary industry

Port Rehabilitation, Maintenance & Asset Renewal (Repairs, Strengthening) (IMAFAJAL)

akta.pro secondary industry

Subsea & Nearshore Civil Works (Trenching, Rock Placement, Mattressing) (IMAFAJAI)

Keywords

• Marine civil engineering
• Port construction services
• Ground improvement
• Coastal infrastructure
• Harbor construction

Headquarters

HQ city

Tokyo

HQ country

Japan

HQ region

Asia

Offices18 records

Markets served

GTM type

B2B

Offering type

Services

Cost components

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

Revenue model

1. Public Works Construction Contracts: Aomi Construction generates the majority of its revenue through competitive bidding on public works construction projects from national government agencies (Ministry of Land, Infrastructure, Transport and Tourism, regional development bureaus), prefectural governments, municipal governments, and public corporations. Projects include harbor/port construction, coastal protection, airport construction, land improvement, flood control, and road/bridge construction.
2. Private Sector Construction Contracts: Aomi Construction also executes construction contracts for private sector clients including major corporations (e.g., Toyota Motor Corporation for pier renovation work at Yokohama plant), private port operators, and real estate developers.

Go-to-market motion1 record

Distribution channels3 records

Marketing channels5 records

Core offering

Aomi Construction is a Japanese marine civil engineering contractor specializing in port and harbor construction, airport construction on reclaimed land, large-scale maritime ground improvement, seismic reinforcement of existing port infrastructure, coastal protection, and underwater construction. The company executes projects through competitive public works bidding and direct private sector contracts, deploying proprietary construction methods, specialized vessels, and ICT-enabled construction management systems.

Product overview

Aomi Construction (あおみ建設株式会社) is a maritime and civil engineering contractor offering specialized construction technologies across port/airport, ground improvement, disaster prevention, and environmental categories. The core portfolio centers on marine construction including caisson production and installation systems (ケーソン自動注水制御システム), underwater excavation equipment (水中バックホウ・ビッグクラブ), and deep-water foundation construction (大水深基礎捨石均し技術). Ground improvement solutions include static compaction methods (KS-EGG工法), deep mixing technologies (S・MIX工法), and offshore SCP systems. Advanced ICT systems provide positioning, monitoring, and automation capabilities including the multi-path resistant underwater acoustic positioning system (耐マルチパス水中音響測位装置「そこにイルカ」) and various construction management systems. Specialized vessels include the grab dredging vessel「海響」and floating dock AFD-8000.

Differentiator

Problem solved

Functional benefit

Brands

• Big Crab (水中バックホウ・ビッグクラブ): Multi-functional underwater excavation machine - mechanical underwater leveling equipment that replaces manual diver work
• Re-Pier Method (Re-Pier工法)
• Soko ni Iruka (そこにイルカ)
• KS-EGG Method (KS-EGG工法)

Products and services

• Port and Harbor Construction Services Design-build services for quay walls, breakwaters, seawalls, container terminals, and other port infrastructure. Projects have included the Sakatai Port quay wall construction for MLIT and the Nagoya Port Tobashima Wharf south quay wall construction for Chubu Regional Development Bureau.
• Airport Construction Services Construction of airports on artificial islands and reclaimed land, including Kansai International Airport (18m water depth, 5km offshore), Haneda D Runway, Chubu Centrair, and Naha Airport runway extension.
• Re-Pier Seismic Reinforcement Services Seismic strengthening, life extension, and water depth increase of in-service piers using the patented Re-Pier method (Patents No. 4864774, 6360725, 6216340). The retractable strut method enables reinforcement construction without removing the pier superstructure, minimizing operational disruption. Winner of the 4th Infrastructure Maintenance Award - Minister of Land, Infrastructure, Transport and Tourism Award.
• Ground Improvement Services Soft-ground and maritime ground improvement using proprietary methods including KS-EGG/KS-EGG-SE (static compaction sand pile, NETIS KTK-180001-VE), SDP-N/SDP-Net (static densification pile, NETIS KTK-210011-A), S·MIX (large-diameter deep mixing, NETIS QS-240010-A), Giant Tamper method, and maritime SCP (KS-REACT). These methods address vibration, noise, and hard soil layer challenges.
• Underwater Construction Services Mechanized underwater construction services replacing manual diver work, performed using the proprietary Big Crab (水中バックホウ・ビッグクラブ) underwater backhoe. Capable of rock leveling, cable burial, rock breaking, and clay cutting at water depths from -2m to -50m. The 7th generation amphibious model operates from land to -4m water depth without support vessels. NETIS registered: KTK-210012-A.
• Caisson Production and Installation Services Caisson production and installation services using the automated caisson water injection control system (NETIS KTK-120002-VE) and the AFD-8000 floating dock/caisson production vessel built in 2022 for use where land space is unavailable. Remote crane operation and touch-panel ballast control enable unmanned operation.
• Flood Control and Water Resources Construction Construction of water resource infrastructure including canal construction (e.g., Toyokawa Water Resources Phase 2 East Main Line canal), seismic strengthening of weir facilities (e.g., ¥297 billion Tone River large-scale earthquake countermeasure project FY2014-FY2023), and river flood control work for water resource development agencies and prefectural governments.
• Land Reclamation and International Port Construction International logistics terminal development and large-scale port construction including the ¥78 billion Shimizu Port Newoki Area International Logistics Terminal Development project (FY2021-FY2027), and the ¥182 billion Kanjo Futo Reorganization Project. Overseas projects include Busan immersed tunnel (Korea), Hong Kong-Macau Bridge (China), and Ehoara Port construction (Madagascar).

Quantifiable outcome

• Big Crab underwater backhoe achieves 7.2x higher construction capacity compared to manual diver labor (in stone leveling operations), with 10% lower unit cost than manual labor under comparable conditions
• +4 more outcomes

Named customers15 records

Segments3 records

Ideal customer profiles2 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Integration4 records

AI capability4 records

Feature14 records

Partnerships

Ten partnerships are on record, tiered core and minor.

• Nikkenren (Japan Federation of Construction Contractors)coreStrategic or Co-development PartnerAomi Construction participates in Nikkenren's 'Labor Cost Estimate Respect Declaration' initiative, committing to set contract amounts at appropriate labor costs reflecting skilled workers' worth and to guide subcontractors on appropriate wage payments to construction workers.
• Buildee (Construction Site Management Web Service)coreTechnology or IntegrationAomi Construction has adopted Buildee for construction site management across its projects. Labor safety documents are created, submitted, and stored electronically through the Buildee platform. The company provides manuals and training for partner construction companies to join the platform.
• GMO Sign (Electronic Contract Service)Technology or IntegrationAomi Construction introduced GMO Sign electronic contract service in April 2026, enabling cloud-based contract execution and eliminating need for physical document mailing. Subcontractors are required to submit pre-approval forms for electronic contracts under Construction Industry Law Article 19.
• University of TsukubacoreStrategic or Co-development PartnerJoint development of anti-multipath underwater acoustic positioning technology (Patent No. 7049572, applied 2018). Aomi Construction and University of Tsukuba jointly developed signal filtering technology to exclude unnecessary reflected waves for stable, high-precision underwater positioning. Joint academic papers published in Japanese Journal of Applied Physics and multiple domestic conferences.
• Shimizu Corporation (清水建設)coreStrategic or Co-development PartnerIn January 2025, Aomi Construction announced its participation in the Shimizu Corporation Group. This strategic affiliation positions Aomi Construction within a major Japanese general contractor group.
• Port and Airport Research Institute (国立研究開発法人 海上・港湾・航空技術研究所)minorStrategic or Co-development PartnerAomi Construction conducted joint experiments on floating acoustic positioning devices and underwater ICT construction equipment with the Port and Airport Research Institute.
• Shinko Techno Co., Ltd. (シンコー・テクノ株式会社)minorOthersGroup company of Aomi Construction. Listed under group companies on the company's website.
• Inoue Kogyo Co., Ltd. (井上工業株式会社)minorOthersGroup company of Aomi Construction. Listed under group companies on the company's website.
• Shiro Shirasagi Farm (株式会社シラサギファーム)minorStrategic or Co-development PartnerAgricultural corporation co-founded by Aomi Construction in April 2022. Represents Aomi Construction's diversification into agriculture sector and regional revitalization initiatives.
• Shimizu CorporationminorImplementation/ SI/ Consulting PartnerAomi Construction was a subcontractor to Shimizu Corporation for the Toyota Motor Corporation Yokohama Plant Pier No. 3 renovation project.

Scale indicators12 records

Recent moves6 records

Expansion highlights6 records

Broad incumbents

• Taisei Corporation: Major Japanese general contractor with marine construction portfolio including port, harbor, and offshore projects. Competes with Aomi on large-scale public works requiring marine specialty capabilities.
• Kajima Corporation: Major Japanese general contractor with civil engineering portfolio including marine construction. Competes for major port, airport, and infrastructure projects where Aomi also bids.
• Obayashi Corporation: Major Japanese general contractor with marine and offshore capabilities including port construction and reclamation. Competes with Aomi for government tenders and large-scale marine projects.
• Shimizu Corporation: One of Japan's largest general contractors, now Aomi's parent company following January 2026 affiliation. Has substantial marine and offshore capabilities and competes for the same mega-projects where Aomi's specialty capabilities are valued.
• Maeda Corporation: Major Japanese contractor with civil engineering and marine construction portfolio. Competes with Aomi on infrastructure projects including ports, bridges, and ground improvement.

Direct peers

• Tokyu Construction Co., Ltd. Japanese construction company with marine construction division alongside general building work. Competes with Aomi on port and harbor projects while having broader construction exposure.
• Toa Corporation: Major Japanese marine civil engineering and port construction company with comparable portfolio in harbor construction, reclamation, and ground improvement. Direct competitor for public works tenders in Japan.
• Zenitaka Corporation: Japanese specialty construction contractor with marine and heavy civil capabilities. Comparable in scale and project types to Aomi, including port, harbor, and ground improvement work for government clients.
• Penta-Ocean Construction Co., Ltd. Japan's largest marine civil engineering contractor, focused on ports, airports, reclamation, and offshore construction. Directly comparable to Aomi in core marine construction capabilities and government-heavy customer base, but at significantly larger scale (¥600B+ revenue).

Emerging players

• JFE Engineering Corporation: Engineering and construction arm of JFE Group with capabilities in port facilities, marine construction, and infrastructure. Increasingly active in marine civil engineering, partially overlapping with Aomi's port construction work.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat6 records

Key risks6 records

Key highlights7 records

Customer concentration

Compliance4 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles10 records

Subsidiaries2 records

Funding overview

Funding rounds

Investors

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

M&A

Investments

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

Frequently asked questions about Aomi Construction