the first section of line 2, between sakae-machi (current sakae) and shiyakusho, opened in 1965. the line was named meijō line in 1969, and the extension was completed in 1971. line 4 opened its first section between aratama-bashi and kanayama in 1974. the line extension was completed in 2004, making a loop line together with line 2. at the same time, the whole loop line was renamed the meijō line, and the section of line 2 between kanayama and nagoyakō, outside the loop, became the meikō line.