| 1985-05 |
Founded in May 1985 |
| 1985-05 |
May 1985 |
| 1985-05 |
Founded |
| 1985-10 |
Organized into a corporation in October 1985 |
| 1985-10 |
October 1985 |
| 1985-10 |
Established |
| 1987-10 |
Relocated headquarters to current location in October 1987 |
| 1994-04 |
Established Matsumoto sales office in April 1994 |
| 1994-08 |
Registered as a surveying business in August 1994 |
| 1994-11 |
Registered as a geological survey business in November 1994 |
| 1995-01 |
Established Toyama sales office in January 1995 |
| 1995-10 |
Completed new headquarters building in October 1995 |
| 1996-10 |
Established Joetsu sales office in October 1996 |
| 1998-06 |
Registered for measurement certification business of concentration (water and soil), sound pressure level, and vibration acceleration level in June 1998 |
| 1998-10 |
Established environmental investigation department in October 1998 |
| 1998-11 |
Registered as a construction consultant in November 1998 |
| 1999-05 |
Established Gunma Sales Office in May 1999 |
| 1999-07 |
Registered for building beverage water quality inspection in July 1999 |
| 2000 |
Opened Nagaoka Branch and Iida Sales Office in 2000 |
| 2000-04 |
Established Non-Destructive Testing Department in April 2000 |
| 2001-04 |
Established Yamanashi Sales Office in April 2001 |
| 2002 |
Registered as a construction business in 2002 |
| 2002-05 |
Founded Eco Grand Deikei Co., Ltd. in May 2002 |
| 2003-01 |
Registered as a designated investigation agency under the Soil Contamination Countermeasures Law in January 2003 |
| 2003-04 |
Opened Minami-Shin Sales Office in April 2003 |
| 2003-07 |
Obtained ISO 9001 certification in July 2003 |
| 2003-10 |
Established DK Technical Research Institute in October 2003 |
| 2004-06 |
Opened Niigata Sales Office in June 2004 |
| 2005-02 |
Opened Utsunomiya Sales Office in February 2005 |
| 2005-04 |
Opened Keiji Sales Office in April 2005 |
| 2005-06 |
Launched Yahoo! Shopping site in June 2005 |
| 2005-09 |
Opened Yokohama Sales Office in September 2005 |
| 2005-12 |
Opened Osaka Sales Office in December 2005 |
| 2006-03 |
Registered as an ISO/IEC 17025 JNLA testing laboratory in March 2006 |
| 2006-10 |
Opened Tokyo Branch in October 2006 |
| 2007-05 |
Opened DK Testing Center in May 2007 |
| 2007-08 |
Opened Nagoya Branch in August 2007 |
| 2008-01 |
Opened Online Shop WEB Testing Center in January 2008 |
| 2008-04 |
Opened Saitama Sales Office in April 2008 |
| 2008-09 |
Opened Ibaraki Sales Office in September 2008 |
| 2009-04 |
Opened Shizuoka Sales Office in April 2009 |
| 2009-07 |
Opened Akita Sales Office in July 2009 |
| 2009-08 |
Opened Kanagawa Sales Office in August 2009 |
| 2009-10 |
Opened Kanto Branch in October 2009 |
| 2009-12 |
Opened Fukushima Sales Office in December 2009 |
| 2011-04 |
Opened Ishikawa Branch in April 2011 |
| 2011-05 |
Registered as First-Class Architect Office in May 2011 |
| 2011-10 |
Opened Tohoku Branch in October 2011 (Reorganization of Fukushima Sales Office) |
| 2012-05 |
Opened Wakayama Branch in May 2012 |
| 2013-07 |
Launched DK Total Support Online Shop in July 2013 (Integrated WEB Testing Center) |
| 2013-07 |
Opened Tokyo Branch in July 2013 |
| 2013-11 |
Expanded DK Testing Center in November 2013 and renamed it Central Testing Center |
| 2013-11 |
Patent registered for "DK-PZX Automatic Flat Plate Loading Test Device" (NETIS registration number KT-100031-A, jointly filed with Nagano Instruments) |
| 2014-01 |
Opened Fukui Sales Office in January 2014 |
| 2014-04 |
Opened East Japan Testing Center in April 2014 |
| 2014-10 |
Opened Osaka Branch (reorganized Osaka Sales Office) in October 2014 |
| 2014-10 |
Opened Yamaguchi Branch Office in October 2014 |
| 2014-10 |
Established West Japan Testing Center Preparation Office in October 2014 |
| 2015-04 |
Opened Yamaguchi Branch in April 2015 |
| 2015-07 |
Application for listing on the Second Section of the Tokyo Stock Exchange approved in July 2015 |
| 2015-08 |
Listed on the Second Section of the Tokyo Stock Exchange in August 2015 |
| 2015-09 |
Opened Shimane Branch Office in September 2015 |
| 2016-02 |
Opened Iwate Branch Office in February 2016 |
| 2016-03 |
Opened Kanazawa Branch Office in March 2016 |
| 2016-04 |
Established West Japan Testing Center in April 2016 |
| 2016-06 |
Opened Kyushu Branch in June 2016 |
| 2016-09 |
Received approval for designation on the First Section of the Tokyo Stock Exchange in September 2016 |
| 2016-10 |
Designated on the First Section of the Tokyo Stock Exchange in October 2016 |
| 2017-01 |
Opened Morioka Branch in January 2017 |
| 2017-04 |
Established Tokyo Head Office in April 2017 |
| 2017-04 |
Opened Kumamoto Branch in April 2017 |
| 2018-08 |
Registered as a Compensation Consultant in August 2018 |
| 2018-09 |
Obtained construction industry license from the Minister of Land, Infrastructure, Transport and Tourism in September 2018 |
| 2018-09 |
Opened FC Sapporo Store through partnership with Housing Pile Industry Co., Ltd. in September 2018 |
| 2018-10 |
Established New East Japan Testing Center in October 2018 |
| 2018-10 |
Made I.S.P. Corporation a subsidiary |
| 2019-04 |
Established a Vietnam representative office in April 2019 |
| 2019-10 |
Opened FC Kumamoto store through partnership with Itech Corporation in October 2019 |
| 2020-01 |
Made Earth Plan Corporation a subsidiary in January 2020 |
| 2020-01 |
Made Create Corporation a subsidiary in January 2020 |
| 2020-08 |
Opened FC Wakayama store through partnership with Nawa Construction Corporation in August 2020 |
| 2020-08 |
Made Okinawa Design Center Corporation a subsidiary in August 2020 |
| 2021-01 |
Opened FC Tokai store through partnership with Chubu Construction Corporation in January 2021 |
| 2021-04 |
Opened FC Fukushima store through partnership with Disk Corporation in April 2021 |
| 2021-06 |
Established DK Online Testing Center in June 2021 |
| 2021-06 |
Opened FC Utsunomiya store through partnership with Matehansa Service Corporation in June 2021 |
| 2021-07 |
Opened FC Kyoto store through partnership with Hills Research and Fields Corporation in July 2021 |
| 2021-07 |
Opened FC Ibaraki store through partnership with M's Act Corporation in July 2021 |
| 2021-07 |
Opened FC Niigata store through partnership with Shuwa Corporation in July 2021 |
| 2021-09 |
Launched DK Note service site in September 2021 |
| 2021-10 |
Opened FC Morioka store through partnership with Kyodo Geological Center Corporation in October 2021 |
| 2021-11 |
Opened Okinawa branch office in November 2021 |
| 2022-03 |
Established Hokkaido branch, Georobotics Research Institute, and Sapporo branch office in March 2022 |
| 2022-04 |
Transitioned to the Tokyo Stock Exchange Prime Market in April 2022 |
| 2022-06 |
Opened FC Chiba store through partnership with OPEN Corporation in June 2022 |
| 2022-07 |
In July 2022, it became a subsidiary of Environment and Development Co., Ltd. |
| 2022-12 |
In December 2022, registered "On-vehicle Radar Exploration Vehicle for Floor Deterioration Inspection Technology" (NETIS registration number KT-220164-A) |
| 2023-04 |
In April 2023, renewed the corporate website. |
| 2023-06 |
In June 2023, launched a recruitment website. |
| 2023-10 |
In October 2023, transitioned to the Tokyo Stock Exchange Standard Market. |
| 2023-10 |
In October 2023, joined the 30by30 Alliance. |
| 2024-04 |
In April 2024, relocated the Sapporo branch. |
| 2024-04 |
In April 2024, opened the Ishikawa branch. |
| 2025-04 |
In April 2025, held a commemorative ceremony for the 40th anniversary of founding and the 10th anniversary of listing. |
| 2025-09 |
In September 2025, Georobotics Research Institute Forest was certified as a Nature Coexistence Site. |
| 2026-01 |
In January 2026, absorbed I.S.P. Corporation into Civil Engineering Management General Testing Institute Co., Ltd. |
