Kyowanissei Co., Ltd. engages in the provision of gas works; building and facility works; electrical and civil engineering works; and integrated facility works. It operates through the following segments: Gas Works, Construction and Public Works, and Others. The Gas Works segment includes the gas pipeline and facility construction; heating, cooling and hot water supply; and air conditioning facility construction services. The Construction and Public Works segment covers plumbing and sanitary works, electrical facility construction, irrigation works, and general public works. The Others segment handles the gas equipment sales, installation, and repair; gas stopper business; and gas facility safety inspection services. The company was founded on September 15, 1948 and is headquartered in Tokyo, Japan.