| Oct 1977 | HOYO Harness Industry Co., Ltd. established |
| Oct 1984 | Changed company name to HOYO SEIKO Co., Ltd. |
| May 1985 | Start of plastic injection molding |
| Aug 1985 | Expansion of head office factory |
| Apr 1987 | Light shielding painting, putting printing technology from Canon to Oita Technology transfer |
| Jan 1988 | Presentation of case at prefectural technology transfer presentation meeting |
| Apr 1988 | Capital increased to 11.4 million yen |
| Nov 1988 | Osoe factory new construction
Molding / Automotive Parts Assy Relationship Relocation |
| Apr 1989 | Capital increased to 16 million yen |
| Jun 1989 | Oita Workplace opened |
| Nov 1989 | Oita Prefecture Small Business Frontier Award Winner |
| Sep 1990 | Oita factory new construction |
| Mar 1991 | Coating Division OK Coating Established |
| Sep 1991 | Capital increased to 20 million yen |
| Apr 1992 | Established HOYO Service Co., Ltd. |
| Feb 1993 | Capital increased to 30 million yen |
| Oct 1993 | Established HOYO Engineering Co., Ltd. |
| Oct 1993 | Capital increased to 50 million yen |
| Dec 1994 | Oita Canon Inc. Quality Improvement Award |
| Nov 1995 | HOYO Shoji founded limited company |
| Nov 1996 | Oita factory video assembly building new construction |
| Feb 1997 | Established HOYO Met Inc. |
| Apr 1998 | Establishment of HOYO Enterprise Cooperative Association |
| Sep 2000 | Nakatsu factory started operation |
| Nov 2000 | Horizontal automatic insert molding technology introduction
(For Nissan Motor Corporation) |
| Dec 2000 | Shonai factory started operation |
| Aug 2000 | Introduction of horizontal LPM technology
(For Toyota Motor Corporation) |
| Aug 2002 | Acquired ISO 9001 |
| Sep 2003 | Acquired ISO 14001 |
| Apr 2004 | Nakatsu factory closed down, integrated into HOYO Met |
| May 2004 | New building of molding factory building of HOYO Met Ltd. |
| Apr 2005 | Insight assembly is begun in the Canon Oita business establishment |
| Apr 2006 | Introduction of aluminum vapor deposition technology
(For Mazda Motor Corporation) |
| Oct 2006 | Introduction of hot plate welding technology
(For Mazda Motor Corporation) |
| Mar 2007 | Capital increased to 60 million yen |
| May 2007 | HOYO Met multicolored painting line Operation end |
| Aug 2009 | Started production of "Fiber painted robot line" in-house developed |
| Apr 2010 | Established Koyo Green Foods Co., Ltd. |
| Aug 2010 | Establishment of Fukuoka factory(Asakura-gun, Fukuoka) |
| Sep 2010 | Fukuoka factory started operations |
| Jul 2011 | Establishment of Hubei HOYO Automobile Zero Parts Co., Ltd.
(Yubeong City, Hubei province) |
| Mar 2013 | Developed horizontal automatic insert molding machine at Osoe factory |
| Apr 2013 | Construction of new head office building |
| Dec 2013 | Establishment of Kitakyushu factory(Tagawa-gun, Fukuoka) |
| Apr 2014 | HOYO Met Expansion of horizontal automatic insert molding machine |
| Oct 2014 | Hubei HOYO Automobile Zero Parts ISO / TS 16949: 2009 certification acquired |
| Jan 2015 | Started mass production at Kitakyushu factory "Fiber painting line" |
| Oct 2016 | HOYO SEIKO 40th Anniversary |
| Sep 2017 | Renovated Oita Hasama Plant V and started production of camera unit parts |
| Dec 2018 | Close the Oita Shonai Plant and consolidate it into the Oita Hasama Plant |
| Dec 2018 | Established in Fudian District, Wuhan City, Hubei Province, China, Wuhan HOYO Seiko Auto Parts Co., Ltd. |
| Jan 2019 | HOYO Shoji completes a rental apartment "Verspah Minami Tateishi" (1 LDK, 20 units) in Beppu Minami Tateishi |
| Mar 2019 | Increased capital to 70 million yen(Employee stock ownership) |
| May 2019 | Constructed a shipping port (480㎡) for Toyota Motor Kyushu milk run at the Kitakyushu factory and started operation |
| Mar 2020 | Increased capital to 72 million yen(Employee stock ownership) |
| Mar 2021 | Increased capital to 88 million yen(Third-party allotment) |
