| Apr 1st 1954 | Nagata Seisakusho was established |
| April 1st 1968 | Head Office is moved to Daiei-cho,Okaya City (current location). |
| Jan 4th 1972 | Nagata Sesakusho is reorganized into Nagata Seisakusho Ltd. |
| Sep 2nd 1987 | Delivery Center is constructed. |
| Sep 1st 1988 | Nagata Co., Ltd. is established. |
| May 21st 1992 | Ibaraki Office is opened. |
| Apr 1st 1994 | Sun-Bright Co., Ltd. joins the Group. |
| Jun 21st 1994 | Akita Office is opened. |
| Dec 1st 1995 | Gosho Factory of Nagata Seisakusho Ltd. is newly built. |
| Jan 1st 1997 | Nagata Seisakusho Ltd. is reorganized into Nagata Seisakusho Co., Ltd. |
| Mar 1st 1998 | Kato Dia Ltd. is founded. |
| Feb 10th 1999 | Sendai Office is opened. |
| Jul 1st 2000 | Head Office of Suntec Dia Co.,Ltd. is newly built in new location.Kato Dia Ltd. is reorganized as Suntec Dia Co., Ltd. |
| Oct 2001 | Jakarta Branch Office is opened. |
| Jan 1st 2002 | Tokyo Office is opened. |
| Apr 1st 2002 | Nagata Hong Kong Co.,Ltd. Is established. |
| Jan 1st 2004 | Kanto Business Office is opened. |
| Apr 1st 2004 | 50th anniversary of Nagata Seisakusho Co.,Ltd.is celebrated. |
| Dec 1st 2004 | Nagata Shanghai International Trade Co.,Ltd. Is established. |
| Mar 1st 2005 | Ustunomiya Office is opened. |
| Dec 2006 | Head office, Gosho factory, Ustunomiya office gained ISO14001 certification |
| Jul 1st 2008 | New Head Office is completed. |
| Jan 1st 2009 | Tokyo office is moved to current location |
| Dec 2009 | Tokyo office gained ISO14001 certification |
| Jan 2010 | Osaka Business Office is opened. |
| Apr 2010 | Oikawa factory is opened |
| Jul 2010 | PT.Nagata Opto Indonesia is opened. |
| Mar 2017 | Utsunomiya office is moved to current location |
| Apr 2020 | Oita Business Office is opened. |