Midōsuji Line

The line was the first subway in Osaka and the first publicly operated subway in Japan, the second subway line in the country overall after Tokyo's Ginza Line. Its construction in the early 1930s was undertaken partly to provide work for Osaka's many unemployed during the Depression. The first tunnel, from a temporary Umeda station to Shinsaibashi, together with the Umeda depot, was dug almost entirely by hand and opened on 20 May 1933 after being plagued by cave-ins and water leakage in the poor ground beneath northern Osaka. The first cars had to be hauled onto the line by manpower and pack animals from the nearby Government Railway tracks. Although trains ran at first as single cars, the stations were designed from the outset to accommodate formations of up to eight cars.

The line was then extended in stages. The permanent Umeda station opened on 6 October 1935, and later that month, on 30 October 1935, the line reached Namba; it was carried on to Tennōji on 21 April 1938. Construction halted during the Second World War — during the Osaka air raids of March 1945 the subway stations are said to have been opened and evacuation trains run to help residents flee — and resumed only afterwards, reaching Shōwachō on 20 December 1951 and Nishitanabe on 5 October 1952.

Through the postwar decades the line continued to grow at both ends and to lengthen its trains. It was extended south from Nishitanabe to Abiko on 1 July 1960, while to the north the Shin-Osaka–Umeda section opened on 24 September 1964, tying the new Shinkansen interchange into the network. Car formations grew steadily from the original single units to four cars in 1953, six in 1958 and eight by 1963. On 24 February 1970 the line was extended north from Shin-Osaka to Esaka, and on the same day through services began with the Kita-Osaka Kyuko Railway, whose line beyond Esaka functions as an extension of the Midōsuji Line; automatic train control was introduced across the whole line at the same time. The route name "Midōsuji Line" itself had been formally adopted on 6 December 1969.

The network reached its present extent on 18 April 1987, when the Abiko–Nakamozu section opened and the line was completed end to end, after which the stations were rebuilt to take longer trains and all services were regrouped into nine-car formations that August. Further refurbishment in the mid-1990s allowed ten-car trains, which became universal on 1 September 1996. Women-only cars were introduced on 11 November 2002.

For most of its history the line was run by the Osaka Municipal Transportation Bureau, but on 1 April 2018 the Osaka municipal subway was corporatised and the Midōsuji Line, along with the rest of the network, passed to the newly formed Osaka Metro Co., Ltd. (大阪市高速電気軌道). The change of operator was seamless to passengers.

Today the Midōsuji Line is the core artery of Osaka's urban transport and the most profitable line on the Osaka Metro network, connecting the city's principal terminals — Shin-Osaka, Umeda, Namba and Tennōji — in a nearly straight line. Its busiest stretch, between Umeda and Yodoyabashi, remains the most heavily used subway section in Japan, and through running onto the Kita-Osaka Kyuko Railway at Esaka extends its reach north toward Senri-Chūō. Platform screen doors, installed line-wide between 2015 and 2022, and on-board services such as free Wi-Fi reflect the continuing modernisation of Osaka's oldest subway.

• 193320 May: the line opens between a temporary Umeda station and Shinsaibashi (3.1 km) as the first subway in Osaka and Japan's first publicly operated subway; trains run as single cars on a single track.
• 19356 October: the permanent Umeda station opens; on 30 October the line is extended from Shinsaibashi to Namba (0.9 km).
• 193821 April: the line is extended from Namba to Tennōji (3.4 km); construction then halts during the Second World War.
• 195120 December: postwar construction resumes, extending the line from Tennōji to Shōwachō (1.8 km).
• 19525 October: the line is extended from Shōwachō to Nishitanabe (1.3 km).
• 19601 July: the line is extended from Nishitanabe to Abiko (2.5 km); seven-car operation begins.
• 196424 September: the Shin-Osaka–Umeda section opens (3.5 km), connecting the new Shinkansen interchange at Shin-Osaka.
• 19696 December: the route is formally given the name 'Midōsuji Line'.
• 197024 February: the line is extended from Shin-Osaka to Esaka (2.9 km); through services with the Kita-Osaka Kyuko Railway begin and automatic train control is introduced line-wide.
• 198718 April: the Abiko–Nakamozu section (5.0 km) opens, completing the line end to end; stations are rebuilt for nine-car trains, with regrouping completed on 24 August.
• 19961 September: refurbishment for longer trains is completed and all services are regrouped into ten-car formations.
• 200211 November: women-only cars are introduced on the line.
• 20181 April: the Osaka municipal subway is corporatised; the Midōsuji Line passes to the newly formed Osaka Metro Co., Ltd. (大阪市高速電気軌道).