Karasuma Line

Kyoto came relatively late to subway construction. A groundbreaking ceremony for the Karasuma Line was held at Gōō Shrine on 29 November 1974, and the first section, between Kitaōji and Kyoto Station, opened on 29 May 1981 as the city's first subway. The new 10 series trains entered service on the same day, running a short north-south spine through the heart of the old capital under Karasuma Street.

The line was then extended in stages. On 11 June 1988 it was carried south from Kyoto Station to Takeda, reaching the point at which it could meet the Kintetsu Kyoto Line. Only weeks later, on 28 August 1988, mutual through-running with the Kintetsu Kyoto Line began, with services running from Kitaōji through to Shin-Tanabe on the Kintetsu side; Kintetsu 3200 series trains began appearing on the subway from that date.

Extension continued at the northern end. On 24 October 1990 the line was pushed north from Kitaōji to Kitayama. The final section followed on 3 June 1997, when the stretch from Kitayama to Kokusaikaikan opened, completing the line to its present length of 13.7 kilometres. Shortly before, on 22 May 1997, Oike Station was renamed Karasuma Oike Station, ahead of the opening of the Municipal Subway's second line, the Tōzai Line. (Japanese Wikipedia lists the rename together with the 3 June completion; English Wikipedia dates it to 22 May.)

Through-service onto the Kintetsu network deepened over time. During the COP3 climate conference in December 1997 a temporary through-service was run between Kokusaikaikan and Takanohara to help carry visitors to the meeting. Then, on 15 March 2000, regular express through-services began running from Kokusaikaikan all the way to Kintetsu Nara, with Kintetsu 3220 series trains introduced for the purpose, giving Kyoto's subway a direct daytime link to Nara.

In the decades since completion the Karasuma Line has continued to be modernised, including the introduction of new 20 series trains from 26 March 2022 to begin replacing the original 1981-vintage 10 series fleet. Together with the east-west Tōzai Line, the Karasuma Line forms the backbone of rail transit within Kyoto, carrying north-south traffic under one of the city's principal avenues and feeding the wider Kinki region through its Kintetsu connections.

• 197429 November: a groundbreaking ceremony for the Karasuma Line is held at Gōō Shrine.
• 198129 May: the first section, Kitaōji–Kyoto, opens as Kyoto's first subway; the 10 series trains enter service.
• 198811 June: the line is extended south from Kyoto Station to Takeda.
• 198828 August: mutual through-running with the Kintetsu Kyoto Line begins, with services running from Kitaōji to Shin-Tanabe; Kintetsu 3200 series trains begin operating on the line.
• 199024 October: the line is extended north from Kitaōji to Kitayama.
• 199722 May: Oike Station is renamed Karasuma Oike Station, ahead of the opening of the Tōzai Line.
• 19973 June: the final section, Kitayama–Kokusaikaikan, opens, completing the line at 13.7 km.
• 19971–10 December: a temporary through-service is run between Kokusaikaikan and Takanohara to carry visitors to the COP3 climate conference.
• 200015 March: regular express through-services begin running from Kokusaikaikan to Kintetsu Nara; Kintetsu 3220 series trains are introduced.
• 202226 March: the new 20 series trains enter service, beginning replacement of the original 10 series fleet.