Mooka Line

The railway began life as a state-built light line. Construction of the Mōka Light Railway started on 15 October 1911, and the first 16.5-kilometre section between Shimodate and Mōka opened on 1 April 1912. The line was then extended in stages: the 12.0-kilometre Mōka–Nanai section opened on 11 July 1913, and the final 13.5-kilometre stretch from Nanai to Motegi opened on 15 December 1920, completing the through route at a length then recorded as 42.0 kilometres. On 2 September 1922 the route was renamed simply the Mōka Line.

Motive power and services evolved over the following decades. Railcar operation between Shimodate and Motegi began on 15 December 1935, and on 1 April 1955 the new stations of Tadara and Kita-Mōka were opened alongside the introduction of diesel railcars. Through limited-express-style services also reached the line: the semi-express "Tsukubane" began running between Ueno, Shimodate and the Mōka and Motegi area on 1 October 1962, was upgraded from semi-express to express on 5 March 1966, and ceased operating onto the Mōka Line on 1 October 1968 when it was converted to electric multiple-unit stock that the unelectrified line could not accommodate.

Steam haulage of regular trains ended on 1 October 1970 with the line's "de-steaming" (無煙化). Freight, meanwhile, was wound down: freight operations between Mashiko and Motegi were abolished on 1 October 1978, and the remaining Shimodate–Mashiko freight service ended on 1 November 1982, ending freight on the line entirely. As a lightly used rural route, the Mōka Line was designated a Specified Local Line slated for conversion, and its abolition as a Japanese National Railways line was approved on 11 September 1984.

With the privatisation of Japanese National Railways on 1 April 1987, the line passed to the East Japan Railway Company (JR East). The third-sector handover followed soon after: on 11 April 1988 the JR Mōka Line was abolished and the Mōka Railway Mōka Line opened in its place, with the operating length adjusted to 41.9 kilometres. Under the new operator the line gained several new stations — Kitayama on 11 March 1989, and Higuchi, Sasaharada and Tenyaba on 14 March 1992 — and passing loops were restored at Nishidai and Ichihana in December 1993.

The Mōka Railway's signature attraction arrived on 27 March 1994, when the steam-hauled "SL Mōka" entered service; turntables to handle the locomotives were completed at Mōka and Motegi stations on 22 March 1996. The line has used JNR-built tank locomotives for the trains, with C12 No. 66 in service and C11 No. 325 used in earlier years, the latter being transferred to the Tōbu Railway on 30 July 2020.

The line was halted in full by the Tōhoku earthquake of 11 March 2011; service resumed on the Mōka–Motegi section on 23 March 2011 and across the whole line on 1 April 2011. In October 2011 the line's Gogyō-gawa and Kokai-gawa bridges were recognised as civil-engineering heritage. The "SL Mōka" was suspended on 7 March 2020 to help curb the spread of COVID-19 and resumed operation on 18 July 2020.

• 191115 October: construction of the state-built Mōka Light Railway begins.
• 19121 April: the first section, Shimodate–Mōka (16.5 km), opens.
• 191311 July: the line is extended from Mōka to Nanai (12.0 km).
• 192015 December: the Nanai–Motegi section (13.5 km) opens, completing the through route at a length of 42.0 km.
• 19222 September: the route is renamed the Mōka Line.
• 193515 December: railcar operation begins between Shimodate and Motegi.
• 19551 April: Tadara and Kita-Mōka stations open; diesel railcar operation begins.
• 19621 October: the semi-express 'Tsukubane' begins running between Ueno, Shimodate and the Mōka/Motegi area.
• 19681 October: the 'Tsukubane' (express since 1966) is converted to EMU stock and ceases running onto the unelectrified Mōka Line.
• 19701 October: regular steam haulage ends with the line's 'de-steaming' (無煙化).
• 19821 November: the last freight service (Shimodate–Mashiko) is abolished, ending freight on the line (Mashiko–Motegi freight had ended 1 October 1978).
• 198411 September: abolition of the line is approved; it is designated a Specified Local Line for conversion.
• 19871 April: with the privatisation of Japanese National Railways, the line passes to JR East.
• 198811 April: the JR Mōka Line is abolished and the Mōka Railway Mōka Line opens in its place; length adjusted to 41.9 km.
• 199427 March: the steam-hauled 'SL Mōka' enters service.
• 199622 March: turntables for the steam locomotives are completed at Mōka and Motegi stations.
• 201111 March: the whole line is suspended by the Tōhoku earthquake; service resumes Mōka–Motegi on 23 March and across the whole line on 1 April.
• 202030 July: C11 No. 325 is transferred to the Tōbu Railway; the 'SL Mōka', suspended 7 March for COVID-19, had resumed on 18 July.