| 1956-09-20 |
Established Hokuriku Sekisan Industry Co., Ltd. and started gravel production and sales. Received construction industry registration and began contracting paving and civil engineering works. |
| 1962-11 |
Changed the company name to Sekisan Industry Co., Ltd. (formerly Hokuriku Sekisan Industry Co., Ltd.). |
| 1962-11 |
Changed company name from Hokuriku Sekisan Industry Co., Ltd. to Sekisan Industry Co., Ltd. Established Kanazu Pile Factory and started production of concrete piles. |
| 1962-11 |
Changed company name to Sekisan Kogyo Co., Ltd. (formerly Hokuriku Sekisan Kogyo Co., Ltd.). Established Kanazu Pile Factory and started concrete pile production. |
| 1963-06 |
Listed on the Osaka Securities Exchange Second Section. Established Osaka Sales Office (now Osaka Branch). |
| 1963-06 |
Listed on the Osaka Securities Exchange Second Section. Established Osaka Sales Office (now Osaka Branch) |
| 1964-11 |
Established Tokyo Sales Office (now Tokyo Branch). |
| 1964-11 |
Established Tokyo Sales Office (now Tokyo Branch) |
| 1967-05 |
Constructed Ibaraki Factory (now Tokyo Sekisan Co., Ltd.) in Sakai Town, Ibaraki Prefecture. |
| 1967-05 |
Constructed Ibaraki Factory (now Tokyo Sekisan Co., Ltd.) in Sakaimachi, Ibaraki Prefecture |
| 1968-06 |
Established Shiga Sekisan Co., Ltd. |
| 1968-06 |
Founded Shiga Sekisan Co., Ltd. |
| 1970-09 |
Acquired exclusive rights to Shake Block and started operations. |
| 1970-09 |
Acquired exclusive implementation rights for Shake Block and commenced operations |
| 1971-07 |
Established Nagoya Sales Office (now Nagoya Branch). |
| 1971-07 |
Established Nagoya Sales Office (now Nagoya Branch) |
| 1977-09 |
Started production of concrete pole products at Tokyo Pile Factory. |
| 1977-09 |
Started production of concrete pole products at Tokyo Pile Factory |
| 1980-11 |
Obtained Minister of Construction certification for Neding construction method. |
| 1980-11 |
Obtained Construction Minister Certification for Neding Construction Method |
| 1983-03 |
Changed the company name to Mitani Sekisan Co., Ltd. (formerly Sekisan Industry Co., Ltd.). |
| 1983-03 |
Changed company name from Sekisan Kogyo Co., Ltd. to Mitani Sekisan Co., Ltd. |
| 1985-05 |
Established Tokyo Head Office. |
| 1985-05 |
Established Tokyo Head Office |
| 1987-01 |
Established Chiba Pile Factory. Leased to Max Concrete Co., Ltd. (now Chiba Sekisan Co., Ltd.), a subsidiary. |
| 1987-01 |
Established Chiba Pile Factory. Rented to subsidiary Max Concrete Co., Ltd. (now Chiba Sekisan Co., Ltd.) |
| 1990-03 |
Completed the Mitani Building tenant office building in Omiya and started office leasing business. |
| 1990-03 |
Completed Mitani Building, a tenant building in Omiya, and started office building leasing business |
| 1994-10 |
Established Shikoku Sales Office (now Shikoku Branch). Established Kagawa Sekisan Co., Ltd. |
| 1994-10 |
Established Shikoku Sales Office (now Shikoku Branch). Founded Kagawa Sekisan Co., Ltd. |
| 1996-11 |
Established Okayama Sales Office. Established Okayama Sekisan Co., Ltd. |
| 1996-11 |
Established Okayama Sales Office. Founded Okayama Sekisan Co., Ltd. |
| 1997-04 |
Established Hiroshima Sales Office (currently Hiroshima Branch). |
| 1997-04 |
Established Hiroshima Sales Office (now Hiroshima Branch) |
| 1999-10 |
Transferred Environmental Products Division to Sekisan PC Co., Ltd. |
| 1999-10 |
Transferred environmental products division to Sekisan PC Co., Ltd. |
| 2000-01 |
Obtained certification for SUPER Nailing Method from the Minister of Land, Infrastructure, Transport and Tourism. |
| 2000-01 |
Obtained Super Neding Construction Method, Ministry of Land, Infrastructure, Transport and Tourism Certification |
| 2001-01 |
Established Kyushu Branch. Omuta Sekisan Co., Ltd. joined our group. |
| 2001-01 |
Established Kyushu Branch. Joined Omuta Sekisan Co., Ltd. and our group |
| 2002-12 |
Established Niigata Sales Office. |
| 2002-12 |
Established Niigata Sales Office |
| 2003-04 |
Established Sendai Sales Office. Tohoku Sekisan Co., Ltd. was established. |
| 2003-04 |
Established Sendai Sales Office. Founded Tohoku Sekisan Co., Ltd. |
| 2005-09 |
Mitani Engineering Co., Ltd. joined our group. Fukui Systems Co., Ltd. joined our group. |
| 2005-09 |
Mitan Engineering Co., Ltd. and Fukui Systems Co., Ltd. joined our group |
| 2005-11 |
Gateway Computer Co., Ltd. joined our group. |
| 2005-11 |
Gateway Computer Co., Ltd. joined our group |
| 2006-06 |
Established Kagoshima Kotsu Mitani Sekisan Co., Ltd. |
| 2006-06 |
Established Kagoshima Koatsu Mitan Sekisan Co., Ltd. |
| 2006-07 |
Established Kagoshima Sales Office. |
| 2006-07 |
Established Kagoshima Sales Office |
| 2007-05 |
Kitakyushu Sekisan Co., Ltd. joined our group. |
| 2007-05 |
Kitakyushu Sekisan Co., Ltd. joined our group |
| 2009-01 |
Established Sapporo Branch. Hokkaido Sekisan Co., Ltd. was established. |
| 2009-01 |
Established Sapporo Branch. Established Hokkaido Sekisan Co., Ltd. |
| 2010-03 |
Obtained certification for Hybrid Nailing Method from the Minister of Land, Infrastructure, Transport and Tourism. |
| 2010-03 |
Obtained Ministry of Land, Infrastructure, Transport and Tourism certification for Hybrid Nailing Construction Method |
| 2010-06 |
Tosmaku AI Co., Ltd. and Kankei Co., Ltd. joined our group. |
| 2010-06 |
Tosmaku AI Co., Ltd. and Kankei Co., Ltd. joined our group |
| 2010-06 |
Tosmaku AI Co., Ltd. joined our group. |
| 2010-06 |
Kankei Co., Ltd. joined our group. |
| 2010-06 |
Tosmaku AI Co., Ltd. joined our group. Kankei Co., Ltd. joined our group. |
| 2013-07 |
Listed on the First Section of the Tokyo Stock Exchange. |
| 2013-07 |
Listed on the First Section of the Tokyo Stock Exchange |
| 2014-02 |
Established Sekisan Engineering Support Co., Ltd. |
| 2014-02 |
Established Sekisan Engineering Support Co., Ltd. |
| 2014-04 |
Established Toyama Sales Office. |
| 2014-04 |
Established Toyama Sales Office |
| 2014-10 |
Established Okinawa Sales Office. |
| 2014-10 |
Established Okinawa Sales Office |
| 2022-04 |
Listed on the Standard Market of the Tokyo Stock Exchange. |
| 2022-04 |
Listed on the Standard Market of the Tokyo Stock Exchange |
