Although the line was originally proposed in 1968, construction did not begin until the 1980s, and the first segment from Komagome to Akabane-Iwabuchi opened on November 29,1991.
Although the line was originally proposed in 1968, construction did not begin until the 1980s, partly due to the right-of-way to meguro with Tokyo Metropolitan Bureau of Transportation Mita Line. The first segment from to opened on November 29,1991.