Kumagai Gumi Co., Ltd. is a construction company operating in Japan and internationally. It builds tunnels, roads, bridges, railways, dams, airports and marine ports, as well as water and sewerage, environmental, energy, renewal, ICT civil engineering, housing, office, hotel, commercial, cultural, educational, sports, medical, plant, distribution and timber projects. The company also produces asphalt mixture and paves roads, airports, ports and bridges; provides building renovation services such as surveys, seismic diagnosis and reinforcement, and long-term renovation planning; manufactures steel products for shield tunnels and construction machinery; and runs a steel construction leasing business. In addition, it offers construction and building plans, CAD and information system software services, CAD education, outsourcing and insurance agency services, and operates as a technology trading company for the construction industry. Founded in 1898, it is headquartered in Tokyo, Japan.