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| Brillia品川南大井 | ||||||||
| CCT CONSTRUCTORS CORPORATION | ||||||||
| R3荒川中堤北葛西一丁目地区護岸改築工事 | ||||||||
| ライオンズ錦糸町レジデンス | ||||||||
| 国家石油ガス備蓄基地 波方基地 | ||||||||
| 大成建設グループ | ||||||||
| 東名阪自動車道 しまだ工区 | ||||||||
| 福井公共職業安定所 | ||||||||
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| 石狩湾新港管理組合 |
On July 3, 1929 (Showa 4), Hanshin Construction Port Co., Ltd. was established through joint investment with South Manchuria Railway Co., Ltd. (Mantetsu). Kamesaburo Yamashita became president.
July 3, 1929: Company founded, President Kamesaburo Yamashita appointed.
Company founded, President Yamashita Kamesaburo appointed
In March 1933 (Showa 8), all necessary approvals for the Naruo project were obtained, and in October of the same year, a groundbreaking ceremony was held, marking the start of construction.
In March 1933 (Showa 8), received all necessary approvals to commence construction of the Naruo project.
Approval granted for Naruo construction
In October 1933, a groundbreaking ceremony for the Naruo construction was held.
Commenced construction in October of the same year.
Inauguration ceremony held
Electric pump vessel 'Naruo Maru' launched
Construction of the Saeki Air Squadron site began
With the outbreak of the Second Sino-Japanese War and the onset of wartime conditions, the Naruo project was deemed unnecessary and urgent, making fundraising difficult, and construction was inevitably halted in November 1938 (Showa 13).
Construction was suspended in November 1938 (Showa 13).
Construction suspended
Masayuki Isomura appointed as the second president
End of the war.
After Japan's surrender on August 15, 1945 (Showa 20), the country faced a severe shortage of goods and currency imbalance, leading to explosive inflation. Families, as well as the nation and businesses, struggled to survive day to day.
In November 1945 (Showa 20), the head office was relocated to Kawaguchi-cho, Nishi-ku, Osaka.
Relocated headquarters to Kawaguchimachi, Nishi-ku, Osaka City.
In March 1946 (Showa 21), the company was permitted to participate in construction, and by operating two dredging vessels, it experienced its first post-war breakthrough.
Contracted the Tone River water control works.
In June 1946 (Showa 21), the company and its 100% shareholder Yamashita Shipping Co., Ltd. were designated as a 'restricted company', limiting their voluntary corporate activities.
Received designation as a limited company.
In November 1946, an office was opened in Ajiro Bay, Tottori Prefecture.
Established a Nagasato office in the Nagasato Bay, Tottori Prefecture.
In June 1949 (Showa 24), the restricted company designation was lifted.
Designation as a limited company was lifted.
In July 1949, the special accounting company designation was removed, and a 20th anniversary celebration ceremony was held.
The designation of the special accounting company was revoked, and a 20th anniversary ceremony was held.
In March 1950, shareholder dividends were reinstated.
Resumption of shareholder dividends.
In October 1950, paid-in capital was increased to 10 million yen.
Paid-in capital increased to 10 million yen.
In August 1952, the head office was moved to Fushimi-cho, Higashi-ku, Osaka.
Relocated headquarters to Fushimimachi, Higashi-ku, Osaka City.
In October 1953, capital was increased to 20 million yen.
Capital increased to 20 million yen.
In April 1955, capital was increased to 60 million yen.
Capital increased to 60 million yen.
In November 1956, the Tokyo branch office was upgraded to a Tokyo sales office, strengthening sales in eastern Japan.
Upgrade the Tokyo branch office to a Tokyo sales office, strengthening sales in eastern Japan.
In October 1957, the capital was increased to 120 million yen.
Capital increased to 120 million yen
In November 1957, the electric-pump dredging vessel 'Fushimimaru' was built.
Construction of the electric pump-type dredging vessel 'Fushimimaru'.
In July 1959, a 30th anniversary ceremony was held and the company anthem was established.
Held the 30th anniversary celebration and established the company anthem.
During the Ise Bay typhoon in September 1959, the vessels 'Nagara', 'Kiso', and 'Kusakizamaru' sank, resulting in the loss of six crew members.
The typhoon in Ise Bay caused the sinking of the 'Nagara', 'Kiso', and 'Kusakizakura' vessels, resulting in six fatalities.
In October 1959, the capital was increased to 250 million yen.
In May 1960, the Tokyo sales office was upgraded to a Tokyo branch.
In July 1961, the head office was relocated to Takara-bashi, Higashi-ku, Osaka.
In September 1961, the capital was increased to 550 million yen.
In October 1961, shares were listed on the Osaka Stock Exchange Second Section.
In May 1962, Masayoshi Haga became the third president.
In October 1962, the company was listed on the Tokyo Stock Exchange Second Section.
In October 1962, the capital was increased to 1.1 billion yen.
On May 28, 1964, the company name was changed to 'Toyo Kensetsu Co., Ltd.'.
In August 1964, the company was listed on the First Section of both the Tokyo and Osaka Stock Exchanges.
In September 1964, the gas-turbine electric pump dredging vessel 'Dai-5 Tokai Maru' was built.
Had to wait for 30 years until 1966 (Showa 41).
Resumption of Naruo operations
Toyo Construction Co., Ltd. was re-certified as a Water-Cycle ACTIVE company in the 8th fiscal year of the Water-Cycle Company Registration and Certification System under the Human Resources and Capital category. The evaluation was based on each branch’s active participation in river and coastal cleanup activities.
Researcher Kazuaki Masuda from the Oriental Construction Comprehensive Technology Research Institute presented the results of his research on weather and wave forecasting using AI at the Kobe University RCUSS Open Seminar. He disclosed wave forecasts up to 11 days ahead for 50 nationwide sites, and introduced efforts to apply them to marine civil engineering projects and to enhance resolution. He also explained plans to expand training data and incorporate physical laws in order to apply the system to disaster prevention.
Toyo Construction has secured Package 1 (civil engineering) of the Sihanoukville Port New Container Terminal Expansion Project (NCT2) in Cambodia. The total contract value is about 26.2 billion yen, and the construction period is 36 months, making it the largest project in Cambodia for the company. The project includes a 400‑meter quay, approximately 200,000 square meters of container terminal, and 12 buildings.
Toyo Construction Co., Ltd. introduced HVO-blended fuel oil into the deep mixing treatment vessel "DCM8" owned and operated by its group on September 1, 2026, marking the first domestic case of such fuel being used on workboats engaged in marine civil engineering projects. HVO is a drop-in fuel that does not require engine modifications, but challenges included the complexity of manufacturing approval and tax exemption procedures under local tax law. Toyo Construction collaborated with relevant authorities to streamline the procurement and fueling processes.
Toyo Construction Co., Ltd. was selected for the Ministry of the Environment's 2026 (Reiwa 8) "Carbon Cycle Business Model Demonstration Subsidy Project for Regional Carbon Circulation Led by Private Enterprises". Through a joint proposal, the company will commence a demonstration project that includes the production and supply of e-methane and CO2 fixation. The main demonstration content involves capturing CO2 from the exhaust gases of Aisin Nishio Die Casting Plant and Denso Anjo Manufacturing Plant, liquefying and transporting it, and supplying it as city gas.
Toyo Construction Co., Ltd. will begin airing its 'How Much Can You Love?' television commercial in October 2026 on Nippon TV and TBS affiliates. The commercial conveys the company's commitment not only to buildings and infrastructure but also to people's lives and a sustainable society.
Toyo Construction Co., Ltd. and Miho Village jointly held ‘Experience the Latest in Manufacturing Technology!’ on August 20, 2026. Twenty elementary school students and their parents took part in activities including observing concrete unloading and quality control, making paper models of earthquake-resistant structures and experiencing a high-rise construction site in VR. The event was the 22nd held in connection with Civil Engineering Day.
On September 1, 2026, Toyo Construction held its first company-wide large-scale disaster preparedness drill. A total of 2,087 employees, including group company staff, practiced safety confirmation and establishing a disaster response headquarters in a Nankai Trough earthquake scenario. Response teams coordinated online, held a briefing on employee safety and damage, and received comments from the president. The company plans to continue training and contribute to rapid recovery and reconstruction when disasters occur.
On August 21, 2026, Kazuki Masuda, a researcher at Toyo Construction’s General Technology Laboratory, delivered an invited talk at the 138th Knowledge-Based Systems Research Group meeting of the Japanese Society for Artificial Intelligence, held at Kansai University. Titled “Marine AI Combining Data-Driven Methods and Physical Laws: From Wave Forecasting to Next-Generation Marine Construction Technologies,” the talk covered progress in AI wave forecasting and research tailored to practical needs, including longer forecast periods, broader areas, higher resolution, and communicating forecast variability. It also highlighted challenges such as performance under unseen conditions and prediction uncertainty, and the need to combine AI with observational data and numerical simulations.
A joint proposal by Toyo Construction Co., Ltd. and Ocean Engineering Co., Ltd. for developing cable burial technology suited to Japan’s complex seabed conditions was selected for NEDO’s next-generation new energy demonstration program. The project aims to develop low-cost, environmentally considerate construction methods needed to expand offshore wind power and achieve carbon neutrality by 2050. Drawing on their marine civil engineering and environmental monitoring experience, the companies will combine construction and monitoring technologies to improve subsea cable burial efficiency while protecting the environment.