[2] Through-service trains between Chūō-Rinkan and Minami-Kurihashi cover a total distance of 98.5 km (61.2 mi) in a single run – nearly six times the length of the Hanzōmon Line alone.

The line was initially operated mainly using Tokyu rolling stock, as the first TRTA 8000 series train did not enter service until 1981.

However, the next extension posed political problems, as the original plan had the line run directly under the Imperial Palace to Ōtemachi Station.

Hanzomon Station opened in December 1982, and the full extension around the Imperial Palace, terminating at Mitsukoshi-mae, was not completed until January 1989.

[6] The line, station facilities, rolling stock, and related assets were inherited by Tokyo Metro after the privatization of the Teito Rapid Transit Authority (TRTA) in 2004.

However, Tokyo Metro stated in its initial public offering that its construction operations would cease once the Fukutoshin Line is completed, which cast some doubt as to whether the Matsudo extension will actually be built.