| 1968-06 |
Established as Yamamoto Building Materials Lease Co., Ltd. in Shirai Town, Imba District, Chiba Prefecture (now Shirai City) |
| 1968-06-20 |
Establishment date |
| 1969-01 |
Nagoya Sales Office (now Nagoya Branch) opened |
| 1969-01 |
Established the Technical Department and started structural calculation and drawing work |
| 1969-04 |
Shirai Factory (now Tokyo Factory) opened |
| 1970-02 |
Shirai Factory (now Tokyo Factory) opened |
| 1970-06 |
Nagoya Factory opened |
| 1971-11 |
Head office relocated to Minato Ward, Tokyo |
| 1972-04 |
Started manufacturing steel segments |
| 1973-01 |
Sendai Sales Office (now Tohoku Branch) opened |
| 1974-06 |
Obtained Tokyo Metropolitan Governor's license for general construction business (building construction, scaffolding and earthwork construction) |
| 1974-10 |
Sendai Factory opened |
| 1975-04 |
Started manufacturing H-shaped support scaffolding |
| 1975-06 |
Merged with Goko Steel Structure Co., Ltd., and opened Nagareyama Factory |
| 1976-05 |
Obtained Tokyo Metropolitan Governor's license for steel structure construction business |
| 1978-01 |
Obtained Minister of Construction's license for general construction business (building construction, scaffolding and earthwork construction, steel structure construction) |
| 1978-09 |
Started sales of corrugated pipes and liner plates |
| 1980-09 |
Opened offices in Chiba (currently Chiba Branch) and North Kanto (currently North Kanto Branch) |
| 1981-07 |
Opened Yokohama Office (currently Yokohama Branch) |
| 1981-12 |
Started full-scale sales of construction machinery |
| 1982-10 |
Started construction of soil cement pile wall method |
| 1985-10 |
Opened Mito Office (currently Mito Branch) |
| 1985-10 |
Established Yamaken Rental Co., Ltd. Chiba (currently a consolidated subsidiary Rental System Co., Ltd.) and Yamaken Rental Co., Ltd. Yokohama (currently a consolidated subsidiary Rental System Co., Ltd.), and began multi-store expansion with a subsidiary for small construction machinery rental |
| 1986-01 |
Obtained Minister of Construction's license for specific construction industries (civil engineering, building, steel structure work) |
| 1990-04 |
Started sales of aerial work platforms |
| 1994-07 |
Merged Kawasho Kensetsu Leasing Co., Ltd. to expand sales base, and changed the trade name to Kawasho Lease System Co., Ltd. As a result of the merger, established Osaka headquarters (currently Osaka Sales Department), Okayama, Hiroshima, Shikoku, Kyushu branches, Kagoshima Sales Office (currently South Kyushu Branch), and factories in Osaka, Okayama (renamed Mizushima Factory), Fukuoka, and Kagoshima |
| 1994-07 |
Merged Kawasho Kensai Lease Co., Ltd. to expand sales base, changed trade name to Kawasho Lease System Co., Ltd. and established offices at Osaka headquarters (now Osaka Sales Department), Okayama, Hiroshima, Shikoku, Kyushu branches, Kagoshima sales office (now Minami Kyushu branch), Osaka, Okayama (renamed Mizushima Factory), Fukuoka, and Kagoshima factories |
| 1994-08 |
四国工場開設 |
| 1995-04 |
Listed on the Second Section of the Tokyo Stock Exchange |
| 1996-09 |
中国工場開設 |
| 1996-09 |
Changed the trade name to Jecos Co., Ltd. |
| 1999-04 |
Stocks designated on the First Section of the Tokyo Stock Exchange |
| 1999-04 |
Opened Niigata Branch |
| 2000-06 |
Opened Japan Sea Factory |
| 2002-05 |
Relocated head office to Chuo-ku, Tokyo |
| 2002-10 |
Obtained license from the Minister of Land, Infrastructure, Transport and Tourism for general construction industry (scaffolding and earthwork) and specific construction industries (civil engineering, building, steel structure work) |
| 2004-01 |
Merged Rental System Tokyo Co., Ltd. and Rental System Osaka Co., Ltd., renamed to Reknos Co., Ltd., transferred construction machinery center operations to Reknos Co., Ltd. (currently a consolidated subsidiary Rental System Co., Ltd.), and reorganized construction machinery business |
| 2004-07 |
Merged Reknos Co., Ltd. (currently a consolidated subsidiary Rental System Co., Ltd.) with Rental System Shikoku Co., Ltd. and Rental System Hiroshima Co., Ltd. |
| 2005-08 |
Changed trade name to Jecos Co., Ltd. |
| 2005-10 |
Tokyo and Osaka factories obtained ISO 9001 certification (manufacturing of steel segments) |
| 2013-04 |
Tomisato Machinery Center Opening |
| 2016-04 |
Divided the business in Hokkaido region and succeeded to Jecos Hokkaido Co., Ltd., a consolidated subsidiary |
| 2016-08 |
Consolidated subsidiary Rental System Fuyo Co., Ltd. merged with Reknos Co., Ltd., and changed the trade name to Rental System Kanto Co., Ltd. (now a consolidated subsidiary, Rental System Co., Ltd.) |
| 2016-09 |
Established GECOSS VIETNAM COMPANY LIMITED in Vietnam through joint investment with JFE Steel Corporation |
| 2018-10 |
Naganuma Plant obtained ISO9001 certification (manufacturing of steel structures) |
| 2020-07 |
Merged with the consolidated subsidiary Jecos Hokkaido Co., Ltd., and succeeded in the business in Hokkaido region |
| 2022-04 |
The consolidated subsidiary Rental System Kanto absorbed and merged with Rental System Tohoku Co., Ltd., Rental System Tokai Co., Ltd., Rental System West Japan Co., Ltd., and Rental System Shinetsu Co., Ltd., changed the trade name to Rental System Co., Ltd., and reorganized the construction machinery business |
| 2022-04 |
Acquired all shares of Otowa Koei Co., Ltd. and made it a consolidated subsidiary |
| 2022-04 |
Naganuma Plant reobtained certification as a steel frame manufacturing plant, H grade |
| 2022-06 |
Shares transferred to Tokyo Stock Exchange Prime Market |
| 2023-06 |
Shares transferred to Tokyo Stock Exchange Prime Market |
| 2023-06 |
Acquired shares of FUCHI Pte. Ltd. and became an equity-method affiliate |
| 2024-02 |
Acquired shares of FUCHI Pte. Ltd. and became an equity-method affiliate |
| 2024-02 |
Relocated head office to Bunkyo-ku, Tokyo |
| 2024-04 |
Relocated head office to Bunkyo-ku, Tokyo |
| 2024-04 |
Naganuma Plant reobtained certification as a steel frame manufacturing plant, H grade |
| 2025-08 |
Concluded a capital and business alliance agreement with Mizuho Lease Co., Ltd. |
