| 1977 |
Since its founding in 1977, with the motto 'From a single shelf to new construction,' and the basic policy of 'Providing better houses at lower costs,' we are committed to quality. |
| 1977 |
Founded in 1977. |
| 1977-09 |
September 1977: Founded as an individual business |
| 1977-09 |
Founded as a sole proprietorship with the catchphrase 'From a single shelf to new construction,' focusing on renovation business 'Seisei'. |
| 1991-04 |
April 1991: Established Seiken Construction Industry Co., Ltd. with capital of 10 million yen. |
| 1991-04 |
Established Seisei Construction Industry Inc. with capital of 10 million yen. |
| 2000-05 |
May 2000: Moved the head office from Fukuda, Fukai, Sakai City to 46 Fukuda, Sakai City. |
| 2000-05 |
Relocated head office from Fukai Shimizucho, Sakai City to 46 Fukuda, Sakai City. |
| 2000-11 |
November 2000: Registered as a First-Class Architect Office. |
| 2000-11 |
Registered as a First-Class Architect Office. |
| 2001-05 |
May 2001: Opened three showrooms in Momochō, Sakai City. |
| 2001-05 |
Opened three exhibition halls in Mozu, Takaishi City. |
| 2004-03 |
March 2004: Established Seiken Home Service Co., Ltd. as a sales subsidiary. |
| 2004-03 |
Established Seisei Home Service Inc. as a sales subsidiary. |
| 2005-02 |
February 2005: Established Seiken Housing Center Co., Ltd. as a sales subsidiary. |
| 2005-02 |
Established Seisei Housing Center Inc. as a sales subsidiary. |
| 2005-05 |
May 2005: Made Seiken Estate Co., Ltd. a subsidiary as a sales company. |
| 2005-05 |
Made Seisei Estate Inc. a subsidiary as a sales company. |
| 2005-06 |
June 2005: Made Seiken Corporation Co., Ltd. a subsidiary as a sales company. |
| 2005-06 |
Made Seisei Corporation a subsidiary as a sales company. |
| 2005-09 |
September 2005: Relocated the housing exhibition hall (Sumai-kan Ishizu Store) to Higashi, Hamadera, Sakai City, Osaka Prefecture. |
| 2005-09 |
Relocated the housing exhibition hall (Living Museum Ishizu Store) to Higashi, Hamadera Ishizu-cho, Sakai City. |
| 2006 |
In 2006, successfully listed on the Second Section of the Osaka Stock Exchange (now Tokyo Stock Exchange) (Standard Market), earning strong trust from the local community. |
| 2006 |
In 2006, listed on the Osaka Securities Exchange Second Section (now the Standard Market) of the Osaka Securities Exchange (now Tokyo Stock Exchange). |
| 2006-02 |
February 2006: Listed on the Second Section of the Osaka Securities Exchange. |
| 2006-02 |
Listed on the Osaka Securities Exchange Second Section. |
| 2006-03 |
March 2006: Capital stock of 578 million yen. |
| 2006-03 |
Capital of 578 million yen. |
| 2006-05 |
May 2006: Opened a housing exhibition hall (Living Museum Mikunioka Store) in Sakai-ku, Sakai City. |
| 2006-05 |
Opened a housing exhibition hall (Living Museum Mikunigaoka Store) in Sakai-ku, Sakai City. |
| 2006-10 |
October 2006: Opened a housing exhibition hall (Living Museum Kitano Noda) in Sakae, Higashi-ku, Sakai City. |
| 2006-10 |
Opened a housing exhibition hall (Living Museum Kitano Noda Store) in So, Higashi-ku, Sakai City. |
| 2012-06 |
In June 2012, changed the company name to Seisei Design Studio Inc. and shifted to the construction industry. |
| 2012-06 |
Changed company name to Seisei Design Workshop Inc. and shifted to the construction industry. |
| 2013-07 |
July 2013: Listed on the Second Section of the Tokyo Stock Exchange following the integration of the Osaka and Tokyo Stock Exchanges. |
| 2013-07 |
Listed on the Tokyo Stock Exchange Second Section following the integration of the Osaka and Tokyo Stock Exchanges. |
| 2013-10 |
October 2013: Shifted to real estate leasing business. |
| 2013-10 |
Shifted to real estate leasing business. |
| 2022-04 |
April 2022: Listed on the 'Standard Market' due to the reorganization of the Tokyo Stock Exchange. |
| 2022-04 |
Listed on the 'Standard Market' due to market reorganization of the Tokyo Stock Exchange. |
| 2024 |
In 2024, listed on the Nagoya Stock Exchange Main Market. |
| 2024-09 |
September 2024: Listed on Nagoya Stock Exchange 'Main Market'. |
| 2024-09 |
Listed on the Nagoya Stock Exchange 'Main Market'. |
| 2025-04 |
Merged with Sakai Store as the head office. |
