On 15 October 1971, a railway license was issued to the Kobe Municipal Transportation Bureau to build a subway line linking the Myōdani district to the Shin-Kobe Shinkansen station; construction on the first segment of that line began on 25 November of that year. The first segment of the subway (between Shin-Nagata and Myodani, known as the Seishin Line) opened on 13 March 1977; a second segment of the line (between Shin-Nagata and Okurayama, known as the Yamate Line) opened on 17 February 1982. The line was extended to Shin-Kobe on 18 June 1985; a western extension to Gakuen-toshi (from Myodani) opened that same day. On 18 March 1987, the final segment of the subway line opened between Gakuen-toshi and Seishin-chūō. The
Hokushin Kyuko Electric Railway opened on 2 April 1988, providing service between Tanigami and Shin-Kobe. An infill station () opened in between Seishin-chūō and Ikawadani stations on 20 March 1993, expanding the line to a total of 16 stations. On 17 January 1995, the subway line was shut down due to damage caused by the
Great Hanshin earthquake; the line resumed operation with limited service between Seishin-chūō and Itayado the following day, along with the entirety of the Hokushin Kyuko line. Limited service was resumed across the entire line on 16 February, and full service was restored in March 1995 after repairs were completed, albeit with speed restrictions remaining in place until 21 July of that year. The subway began to accept the
Surotto Kansai smart card in October 1999; it would start accepting
PiTaPa in October 2006.
Women-only cars began to be used on the subway line from 16 December 2002. Currently, one car heading in the direction of Seishin-chūō (car number 4) is reserved for women only; the restriction applies throughout the entire day. ==Stations==