Tracing its heritage to 1873 when Kihachiro Okura established Okuragumi Shokai, Taisei Corporation is one of Japan’s five historic super-general contractors (zenikon). Headquartered in Nishi-Shinjuku, Tokyo, Taisei is an employee-owned construction giant listed on the Tokyo Stock Exchange (Nikkei 225), employing over 14,000 personnel across civil engineering, building construction, engineering consulting, and urban development divisions.

In railway infrastructure, Taisei has played an instrumental role in shaping Japan’s rail network from its Meiji-era origins through the modern high-speed era. Taisei was a lead contractor on the historic Seikan Tunnel—the world’s longest undersea railway tunnel connecting Honshu to Hokkaido—pioneering deep undersea grouting and structural waterproofing under extreme hydrostatic pressures. The firm has delivered major alignment packages across the Tokaido, Tohoku, Joetsu, Kyushu, and Hokuriku Shinkansen networks, encompassing viaduct spans, mountain tunnels, and terminal stations.

Internationally, Taisei is recognized for complex urban and subsea infrastructure delivery. It spearheaded the Marmaray Project in Istanbul, Turkey, constructing the world’s deepest immersed tube railway tunnel beneath the Bosphorus Strait under challenging seismic conditions. In Southeast Asia, Taisei has delivered major mass transit packages, including viaduct and underground sections for the MRT Jakarta (Indonesia), the Singapore MRT Downtown and Thomson-East Coast Lines, and high-capacity airport ground infrastructure.