| 1923 |
Established Nagoya factory in Nagoya City with capital of 30,000 yen, primarily manufacturing and selling patented reinforced concrete pipes (founding) |
| 1923-11-14 |
November 14, 1923 |
| 1923-11-14 |
Founded on November 14, 1923 |
| 1927 |
Established Kyoto sales office and Kyoto factory (abolished in 1979) |
| 1931 |
Moved headquarters to Tokyo |
| 1937 |
Established Tokyo factory |
| 1945 |
Moved Tokyo factory and established Kawasaki factory |
| 1951 |
Kyoto factory received JIS labeling approval for reinforced concrete pipes, pioneering the industry |
| 1957 |
Established Shiga factory |
| 1958 |
Established Wakayama branch office (promoted to sales office in 1973), Wakayama factory, Nagoya sales office, Kasugai factory, moved Kawasaki factory, and established Fuchu factory |
| 1960 |
Our company's shares are listed on the over-the-counter market. |
| 1961 |
Started manufacturing prestressed concrete products, established an Akita factory, and listed our shares on the Second Section of the Tokyo Stock Exchange. |
| 1962 |
Opened a branch office in Kanazawa (promoted to a sales office in 1973), established a Chiba factory (closed in 2005). |
| 1963 |
Opened an Akita branch office (promoted to a sales office in 1973, merged with the Sendai sales office in 2021). |
| 1966 |
The PC box culvert was first adopted as a main sewer line crossing the runway at Itami Airport. |
| 1967 |
Established the Kohoku factory. |
| 1971 |
Established the Sendai factory and a Sendai branch office (promoted to a sales office in 1973). |
| 1973 |
Established the Ena factory and held a 50th anniversary celebration. |
| 1974 |
Formed the ABC Group by consolidating companies that had entrusted our box culvert technology. |
| 1980 |
Established the Ibaraki factory. |
| 1981 |
Established the Japan PC Box Culvert Products Association. |
| 1984 |
Established the National Connect Hole Industry Association. |
| 1985 |
Opened the Hanshin and Chiba sales offices, and established the Kanto factory. |
| 1986 |
Established the PC Seismic Resistance Fireproof Water Tank Association and the Japan Cab System Association. |
| 1988 |
Opened the Saitama sales office and conducted a public offering of 200,000 shares (raising capital to 1.249 billion yen). |
| 1989 |
At the regular shareholders' meeting, decided on changes to the authorized number of shares, the par value per share (from 500 yen to 50 yen), the number of shares per unit, and established the Hyogo factory. |
| 1993 |
Completed the large-scale Phase 1 joint residential trench construction in Makuhari New City. |
| 1995 |
PC rainwater storage tank Aqua installed its first unit in Atami City, established the Japan Rainwater Storage System Association, opened the Shiga sales office, and opened the Kobe branch office (promoted to a sales office in 2015, merged with the Hanshin sales office in 2021). |
| 1997 |
Opened the Yokohama sales office. |
| 2000 |
Obtained construction technology inspection certification for PC rainwater storage tank Aqua, and registered the Kanto factory and design department's quality management system (ISO 9001). |
| 2002 |
Western branch and related facilities registered Quality Management System (ISO 9001:2000) |
| 2004 |
Opened Ibaraki branch office (promoted to office in 2015) |
| 2006 |
Implemented basic policy of internal control system under the Companies Act, registered Quality Management System (ISO 9001:2000) for Eastern branch and related facilities, constructed 1500m³ seismic‑resistant water tank (certified by Japan Fire Equipment Safety Center) No.1 within Takadazemi Park, Kyoto City |
| 2007 |
Registered TB (Touch Bond) method "NETIS", first adopted in Machida City, Tokyo |
| 2008 |
Obtained technical review certification for TB (Touch Bond) method, established TB (Touch Bond) method research association |
| 2009 |
Developed ECO‑C·L (Eco Clean Lift) method |
| 2010 |
Changed the number of shares per unit from 1,000 to 100 |
| 2011 |
Registered ECO‑C·L (Eco Clean Lift) method "NETIS" |
| 2012 |
Registered TB (Touch Bond) method as NETIS KK‑070004‑V (evaluation information), established Tohoku branch and reconstruction‑related business division, RC box calvert and PC box calvert designated as Class I materials by the Japan Sewage Association (JSWAS A‑12, JSWAS A‑13) |
| 2015 |
Merged Eastern branch and Tohoku branch into Eastern Tohoku branch |
| 2016 |
Opened Okinawa sales office and Fukushima office (closed in 2021) |
| 2017 |
Transitioned Western branch and related facilities’ Quality Management System to ISO 9001:2015 (registration number RQ2220), and Eastern Tohoku branch and related facilities’ Quality Management System to ISO 9001:2015 (registration number JSAQ976) |
| 2018 |
Obtained technical review certification for new box‑type Agua |
| 2021 |
In Kōnan City, Aichi Prefecture, the first construction of new box‑type Agua, obtained technical review certification for PPCa box calvert (co‑developed with Tokyu Construction) |
| 2022 |
Patent obtained for new box‑type Agua (Vietnam), PPCa box calvert first constructed in Shibuya (roadway section) |
| 2023 |
Celebrated 100th anniversary, published commemorative corporate history "100 Years of Progress", PPCa box calvert constructed in Shibuya (sidewalk section) |
| 2024 |
Registered PPCa box calvert as NETIS KT‑230338‑A (Kanto Regional Development Bureau), and new box‑type Agua as NETIS KT‑230300‑A (Kanto Regional Development Bureau) |
