The Sakura-dōri Line's color on maps is red and stations are labeled with the prefix "S".

The Sakura-dōri Line was first envisioned in the Urban Transportation Council Report No.

14 (1972) as an underground line running from Nakamura Kuyakusho to Imaike, and was intended to relieve the central portion of the Higashiyama Line, which in the late-1970s operated with a crush load capacity of 250% during rush hour.

Automatic train operation (ATO) using a single driver commenced on 16 February 1994, and the line was extended from Imaike to Nonami on 30 March 1994.

There is also a plan to extend the line to opposite direction, from Nakamura Kuyakusho to somewhere in Ama.