Meitetsu Seto Line

The railway was opened by the Seto Automatic Railway (瀬戸自動鉄道, Seto Jidō Tetsudō) between Owari Seto and Yada on 2 April 1905, and extended it to Ōzone the following year on 1 March.^[3][4] The passenger service was provided by Serpollet [ja] steam-powered railcars, but these proved to be underpowered and unreliable. The line was soon electrified with the first electric-powered train running on 17 March 1907 with 600 V DC. The company changed its name to Seto Electric Railway (瀬戸電気鉄道, Seto Denki Tetsudō) in December 1906.^[5][4] By 1 October 1911, the line was extended to Horikawa, in the outer moat of Nagoya Castle.^[4] The line was duplicated by December 1929.^[4] In 1939, the company merged with Meitetsu.^[6][4] As the line were isolated from any other Meitetsu railway lines, rolling stock used in the line at this time were trains built by Seto Electric Railway or older trains relocated from the main lines of Meitetsu. Some older station buildings from the initial days of the line, such as the station buildings of Ōzone and Owari Seto were also used into the late Shōwa era.^[4]

The Horikawa to Shimizu section closed on 15 February 1976^[4] to allow for the construction of the new line to Sakaemachi and the connection to the Nagoya Subway Higashiyama Line, which opened in 1978. The voltage on the line was raised to 1,500 V DC, and freight services ceased the same year.^[7]