Company profile

Let us tell you about KOJIMAGUMI.

We aim to improve our work efficiency through untiring efforts to develop self-technology, show appreciation to shareholders for their support and protect our employees' living, contributing to society.

Scoop the mud from the bottom of the water to make land.
Humans have been doing so not only in Japan but in many countries since the dawn of history. We hear the story of creation, "the land created with the mud from the bottom of the water," not only in Japan but in other countries as well. People created land from shapeless mud, built houses, paved roads, opened markets, nurtured culture, and generated civilization. It is not an exaggeration to say that civil engineering starts with "dredging" that scoops mud.

Port is where trading with countries around the world to sustain our lives takes place. It has a characteristic nature to get filled with sediment flowing from rivers over time. Accumulated sediment in rivers blocks the flow of water, causing floods. Dredging moves sediment allowing the port to function. And it restores the smooth flow of rivers. Sediment can utilize to create land elsewhere.

Kojimagumi has been engaging in the various port civil engineering business, including dredging in the dynamic natural cycle, since its establishment in 1919. We have participated in construction works in and out of Japan with our many dredgers as the world's largest grab dredger, GOSHO. We also have operated many of our unloader vessels, creating new land utilizing dredged material. We are proud to provide a backbone to society maintaining port activities and protecting people's lives from disasters through business.

Severe climate change. Infectious disease crisis as the novel coronavirus. People are looking for a new way of living, cities, and societies that accommodate various changes now. Also, in ports and rivers, we need a new civil engineering work that enables people a continuous secure life.

Kojimagumi will contribute to creating a new society of continuous secure life, developing advanced civil engineering technology, work vessels, and construction machinery utilizing digital technology actively, reaffirming the fundamental meaning of civil engineering of "creating a society."

President, Representative Director
Tomonori Kojima

Company KOJIMAGUMI Co., Ltd. Capital 90,000,000 JPY
Head office 〒455-0021
1-6 Kiba-cho, Minato-ku,
Nagoya, Aichi, Japan 455-0021 
TEL: +81 52 691 7040
Settlement May annually
Established Jun, 1919 Representative President, Representative Director 
Tomonori Kojima
Reorganized Dec. 1941 Number of
196 (As of May, 2020)
Business Dredging/reclamation, civil engineering works and related activities Constructor
Register No.
Licence obtained by Minister of the Ministry of Land, Infrastructure, Transport and Tourism (Special)26-3337
Work type
Civil engineering/scaffolding

1919 Jun. Establish in Ueno-village, Chita-county, Aichi (Current Nawa-machi, Tokai-city)
1941 Dec. Reorganize (Capital 198,000 yen)
1948 Apr. Start dredging 
(Horikawa river dredging)
1954 Mar. Build a wooden grab dredger 
1957 Sep. Move office to current location
1959 Mar. Build a steel grab dredger
1963 Mar. Increase the capital to 18,000,000 yen
1967 Apr. Open Tokyo branch
1970 Jun. Build an anchorless grab dredger 
1975 Mar. Patent anchorless moving equipment 
(2 Spuds)
Nov. Increase the capital to 36,000,000 yen
1984 Jul. Open Osaka branch
1985 Sep. Build a hydraulic counter weight balance system grab dredger 
1988 May. Increase the capital to 80,800,000 yen
1993 Jul. Build an air pressure transfer vessel (Air pressure vessel) 
1995 Jul. Build a mega grab dredger 
(200m3 Grab bucket) TOSHO
2000 May. Build a second mega grab dredger (200m3 Grab bucket) GOSHO
2004 Aug. GOSHO & TOSHO complete Nakayama channel dredging
2008 Oct. First overseas dredging project in Saudi Arabia (GOSHO)
2012 Apr. First African dredging project in Republic of South Africa (TOSHO)
Sep. Increase the capital to 90,000,000 yen
2014 Jun. First South East Asian dredging project in Singapore (661 RYOSEI MARU)

Tokyo branch

Tokyo branch
Hacchobori Chishima Bldg. 6F, 3-22-11Hacchobori, Chuo-ku, Tokyo 104-0032
TEL +81 3 3297 1681

Osaka branch

Osaka branch
Sando Bldg. 2F, 1-24-5, Himesato, Yodogawa-ku, Osaka 555-0025
TEL +81 6 6477 1161

Yokohama service office

Yokohama Bldg., 3-9 Kaigandori, Naka-ku, Yokohama, Kanagawa 231-0002
TEL+81 45 201 7016

Ibaraki service office

Fujihiro Bldg., 217-2 Kyuchu, Kashima, Ibaraki 314-0031
TEL +81 299 83 8799

Chita service office

8 Suzaki, Nawa-machi, Tokai, Aichi 476-0002
TEL +81 52 601 0169

Tokoname service office

1-95 Shinkai-cho, Tokoname, Aichi 479-0837
TEL +81 569 34 9793

Ama servise office

1-16 Kusunoki, Yatomi, Aichi 498-0066
TEL +81 567 68 4100

Kyushu service office

Voice Hakata Bldg. 508, 1-7-14 Hakataeki-minami, Hakata-ku, Fukuoka, Fukuoka 812-0016
TEL +81 92 477 7005

Our founder Ryoichi Kojima once served as a chairman for Ueno (current Tokai-city) town assembly. And the letter "Ryo" from his first name was branded on shovel and other civil engineering work equipments. That is said to be the origin of this logo. Then after being demobilized from the WW2, the third president Akio Kojima (deceased) improved the design by adding the symbol color blue as in the beautiful ocean that surrounds Japan. Heishu Hosoi (born in current Tokai-city), who was a mentor of Yozan Uesugi, Yonezawa's (Yamagata prefecture) lord of feudal clan and a renowned Confucian scholar in Edo era, being greatly respected at his birth town, said "All of learning, thinking and acting together complete the good." That also expresses the core philosophy of our company, which is aiming to contribute to the society through learning on site, thinking and acting.

President, Representative Director Mitsuo Watabe
Toyoken Bldg. 4F, 2-16-13 Tenma, Atsuta-ku, Nagoya,
Aichi, Japan 456-0034
TEL +81-52-683-7335

DAMDRE Co., Ltd.
President, Representative Director Tsutomu Sato
Yaesu No.3 Nagaoka Bldg. 6F, 3-22-11Hacchobori, Chuo-ku, Tokyo, Japan
TEL +81 3 5542 3530

President, Representative Director Michihiro Kimura
1-6 Kiba-cho, Minato-ku, Nagoya, Aichi, Japan 455-0021
TEL +81 52 691 7288

CEO Steeve S.Ryoo
6F Busan Shipyard Bldg, 1, Haeyang-ro 15, Yeongdo-gu, Busan, Korea
TEL +82-51-441-0801