The subsequent progress of the line was as follows: Ochanomizu to Awajichō: March 1956 Awajichō to Tokyo: July 1956 Tokyo to Nishi-Ginza (now Ginza): December 1957 Nishi-Ginza to Kasumigaseki: October 1958 Kasumigaseki to Shinjuku: March 1959 Shinjuku to Shin-Nakano/Nakano-Fujimichō (not Nishi-Shinjuku): February 1961 Shin-Nakano to Minami-Asagaya (not Higashi-Kōenji): November 1961 Minami-Asagaya to Ogikubo: January 23, 1962 Nakano-Fujimichō to Hōnanchō: March 23, 1962 Nishi-Ginza becomes part of Ginza when Hibiya Line reaches there: August 1964 Higashi-Kōenji opens (between Shin-Nakano and Shin-Kōenji): September 1964 Nishi-Shinjuku opens (between Shinjuku and Nakano-Sakaue) May 1996. The Marunouchi Line was one of the lines targeted in the Aum sarin gas attack on March 20, 1995. A plan to extend the Marunouchi Line from Ogikubo to Asaka City in Saitama Prefecture was rejected in the late 1990s. The line, stations, rolling stock, and related facilities were inherited by Tokyo Metro after the privatization of the Teito Rapid Transit Authority (TRTA) in 2004. Automatic train control (ATC) was activated on the Marunouchi Line on February 27, 1998, which allowed for an increase in the maximum operating speed limit from to . This was followed by Train automatic stopping controller (TASC) which was introduced in November 2002, along with Automatic train operation (ATO) which was introduced on the main segment of the Marunouchi Line on December 27, 2008. The platform-edge doors at Hōnanchō Station, the terminus of the Hōnanchō Branch, were lengthened to allow six-car trains to use the station, with work starting in 2013, which enabled through trains to and from Ikebukuro to start operating all the way to Hōnanchō from fiscal 2017. Future plans Communications-based train control (CBTC) signalling is also scheduled to be introduced together with the new rolling stock from 2022. References Shaw, Dennis and Morioka, Hisashi, "Tokyo Subways", published 1992 by Hoikusha Publishing External links Tokyo Metro website Lines of Tokyo Metro Railway lines in Tokyo Railway lines opened in 1954 Standard gauge railways in Japan 1954 establishments in Japan 600 V DC railway electrification