Nankō Port Town Line

The line opened on 16 March 1981 between Nakafutō and Suminoekōen, built and run by the Osaka Municipal Transportation Bureau as the medium-capacity rail spine of the newly reclaimed South Port area. It was an early example of automated guideway transit in Japan, following Kobe's Port Island Line, and used a rubber-tyred people-mover technology guided by a side rail rather than conventional steel wheels on rails.

For its first decade the New Tram ran with staff aboard. Fully unattended automatic operation began on 20 October 1991, when the 100A series trains entered service and the line switched to driverless running under automatic train control.

That automation was interrupted by a serious accident. On 5 October 1993 a train failed to stop at the Suminoekōen terminus and ran into the structure at the end of the line; the Japanese account records 215 people injured, and the whole line was suspended. Services resumed on 19 November 1993, but with crew riding the trains again under semi-automatic operation rather than fully unattended running.

The line was extended at its northern end later in the decade. On 18 December 1997 the New Tram Technoport Line opened from Cosmosquare to Nakafutō, built by the third-sector Osaka Port Transport System (OTS), and through services began between the two lines; the entire line had been suspended for a full day on 31 October 1997 to prepare for the connection. Fully unattended automatic operation was restored on 20 February 2000.

The two halves were later unified under a single operator. On 1 July 2005 the OTS New Tram Technoport Line was merged into the Nankō Port Town Line, so that the through route from Cosmosquare to Suminoekōen became a single line. The 200 series cars entered service on 29 June 2016.

On 1 April 2018 the Osaka Municipal Transportation Bureau was corporatised, and its rail network — including the Nankō Port Town Line — passed to the new company Osaka Metro (formally Osaka Metro Co., Ltd. / 大阪市高速電気軌道), which has operated the line ever since.

• 198116 March: the line opens between Nakafutō and Suminoekōen, built and operated by the Osaka Municipal Transportation Bureau as an automated guideway transit line; service runs with crew aboard.
• 199120 October: fully unattended automatic operation begins; the 100A series trains enter service.
• 19935 October: a train fails to stop at Suminoekōen and runs into the end-of-line structure; 215 people are injured (JA account) and the whole line is suspended.
• 199319 November: operations resume with crew riding the trains under semi-automatic operation rather than fully unattended running.
• 199731 October: the whole line is suspended for the full day to prepare for through-running with the new OTS line.
• 199718 December: the OTS New Tram Technoport Line opens from Cosmosquare to Nakafutō, and through services begin between the two lines.
• 200020 February: fully unattended automatic operation is restored.
• 20051 July: the OTS New Tram Technoport Line is merged into the Nankō Port Town Line, unifying the Cosmosquare–Suminoekōen route under one line.
• 201629 June: the 200 series cars enter service.
• 20181 April: the Osaka Municipal Transportation Bureau is corporatised and the line passes to the new company Osaka Metro (Osaka Metro Co., Ltd.).