After World War II, the ownership of the right-of-way of an uncompleted Imperial Japanese Armymilitary railway line was transferred to Keisei. Shin-Keisei was established as a subsidiary of Keisei on 23 October 1946 to construct and operate the line. The first section of the line, 2.5 km from Shin-Tsudanuma to Yakuendai, was opened on 27 December 1947, with a track gauge of 1,067 mm (3 ft 6 in) and electrified at 1,500 V DC overhead. The line was regauged to 1,372 mm (4 ft 6 in) in October 1953, and the entire line was completed as a single-track line by 21 April 1955. In August 1959, the line was again regauged, this time to 1,435 mm (4 ft 81⁄2 in) to match the standard gauge used by Keisei Electric Railway.
In June 2014, the company unveiled a new corporate image with a new corporate logo and "gentle pink" corporate colour scheme and train livery. The company's entire fleet of trains is scheduled to be reliveried in the new colour scheme, with the first train, an 8800 series set entering service from 29 August 2014.