In September 1981, supported by investment from local organizations and the Teito Rapid Transit Authority, the Toyo Rapid Railway Corporation was established. Work was started in 1985 by the Japan Railway Construction Public Corporation through a funding system whereby the public corporation funds construction on behalf of the operator, who then reimburses the public corporation on completion of construction. Originally the line was conceived as a subway, yet the eventual plan called for roughly two thirds of the line in suburban areas to be elevated.

On April 27 1996, the entirety of the 16.2km line was opened. At the same time, the line also offered a through-service from Nishi-Funabashi Station via the then Teito Rapid Transit Authority Subway Tozai Line. Since the opening of the Toyo Rapid Railway Line, access to the heart of Tokyo for Chiba residents has vastly improved.

The introduction of new rail facilities and stations has had a significant impact on local residents. Despite the area along the railway being one of high population density, for a long time, residents did not benefit from the convenience of such a transit system. From the opening of the line to the present day, there have been no accidents whatsoever, and impeccable safety standards have been maintained. The three precepts of operation: Safety, Independence, and Unity capture the aim of providing a safe, reliable service closely tied to the local community.