the line was originally the part of meijō line. when line 4, the eastern part of the current loop line, was completed in 2004, the whole of the loop (consisting of part of line 2 and line 4) was renamed the meijō line, and the remaining section between kanayama and nagoyakō, outside the loop, became the meikō line. the name meikō derives from the abbreviated "kanji" form of .