June 1. 1938	Established the head quarter in Huruitimachi, Urata-ku, Tokyo, and  Kansai plant in Yamamura, Mukogun, Hyougo.  Since then, Dohwa received orders from Mitsubishi Heavy Industries,  Ltd. and Mitsubishi Motors Corporation as a designed factory for  manufacturing various types of springs.
April. 1945	The war destroyed both plants. Established and relocated the main  plant to Omoriminami, Otaku, Tokyo.
July. 1946	Started manufacturing at the new factory.
April. 1969	Constructed factories and facilities for rationalization and modernization. Since then, efforts have been made to improve quality by installing and  upgrading equipment.
September. 1979	Received recognition as a certified factory from Caterpillar Mitsubishi  Ltd.
September. 1993	Established Gunma plant for the improvement of machining accuracy  and production efficiency.
August.1999	Acquired JIS Q 9000:2000,ISO 9001:2000.
April. 2004	Built Gunma second factory. Built the third factory in May 2008.  Aggregated all production bases to Gunma Plant.
December. 2007	Built new head office at Inagi-shi, Tokyo.  Relocated there in January 2008.
May. 2018	Held 80th Anniversary Event.
March. 2023	Registered to ISO 14001:2015＝JIS Q 14001:2015