Hanawa Line

Unusually, the line was not built as a single project but grew from two ends that were later joined. The first segment to open was on the Ōdate side, built by the private Akita Railway (秋田鉄道), which after receiving its first licence in 1912 opened from Ōdate as far as Ōgita on 1 July 1914 and pushed inland over the following years. The Kōma side, by contrast, was planned by the state under the Light Railway Act and opened in stages as the government's "Hanawa Line" from 1922 onward, advancing west until it met the Akita Railway at Rikuchū-Hanawa in 1931.

The Akita Railway extended its tracks eastward from Ōdate in steps: Ōgita to Ōtaki-Onsen on 19 January 1915, on toward Kemanai for freight by the end of 1915 with passenger service following on 5 January 1916, and finally Kemanai through to Rikuchū-Hanawa on 10 November 1923, completing the private line. The government's Hanawa Line worked in from the Kōma end: Kōma to Tairadate on 27 August 1922, then Tairadate–Akasakata (1926), Akasakata–Araya-Shinmachi (1927) and Araya-Shinmachi–Tayama (1929).

The two halves were united on 17 October 1931, when the state line was extended from Tayama to Rikuchū-Hanawa, where the Akita Railway already had its station. The corridor became a single through route, and on 1 June 1934 the Akita Railway was purchased, nationalised and merged into the Hanawa Line, completing what was now an east–west railway across the Tōhoku region. The state took over the former private company's rolling stock — five locomotives, six gasoline railcars, sixteen passenger carriages and twenty-three freight wagons.

Under national ownership the line was gradually modernised and its services renamed. Diesel railcar operation began on 1 March 1959, and steam haulage ended on 30 September 1971 with the withdrawal of the Class 8620 locomotives, leaving the line fully dieselised. A succession of express and semi-express trains — among them the "Yoneshiro," "Hachimantai" and "Michinoku" — ran over the route during the 1960s and 1970s, and the line also served as a diversionary route for limited expresses such as the "Hatsukari" when the parallel Tōhoku Main Line was blocked, as it was after the 1968 Tokachi-oki earthquake.

All freight operations over the line were abolished on 1 February 1984. With the division and privatisation of Japanese National Railways on 1 April 1987, the Hanawa Line passed to JR East. Several stations were renamed over the following years: Iwate-Matsuo became Matsuo-Hachimantai and Ryūgamori became Appi-Kōgen on 13 March 1988, while Yuze became Yuze-Onsen and Rikuchū-Hanawa became Kazuno-Hanawa on 1 December 1995.

The line's connection at its eastern end changed on 1 December 2002, when the Morioka–Metoki section of the Tōhoku Main Line was transferred to the third-sector IGR Iwate Galaxy Railway; Hanawa Line trains, which had run through onto the Tōhoku Main Line, instead began through-running onto the Iwate Galaxy Railway line, and the express "Yoneshiro" was discontinued. The line was progressively fitted with special automatic block working and centralised traffic control by the end of 1999.

Like many rural lines in the region the Hanawa Line has been repeatedly cut by natural disasters. It was halted by the Great East Japan Earthquake on 11 March 2011, and heavy rain in August 2013 again broke the line. Severe rainfall on 13 August 2022 caused damage at 54 sites between Kazuno-Hanawa and Ōdate, closing that section until full services resumed on 14 May 2023; further flooding on 20 August 2025 cut the same section again, with through services restored on 26 September 2025. The line remains a lightly used regional route whose continued operation has become the subject of local-government promotion efforts.

• 19141 July: the private Akita Railway opens its first section, Ōdate–Ōgita, on the Ōdate (Akita) side of what becomes the Hanawa Line.
• 191519 January: the Akita Railway extends from Ōgita to Ōtaki-Onsen; by 25 December it reaches Kemanai (freight).
• 19165 January: passenger services begin on the Ōtaki-Onsen–Kemanai section of the Akita Railway.
• 192227 August: the Japanese Government Railways open the state-built Hanawa Line from Kōma to Tairadate on the Kōma (Iwate) side.
• 192310 November: the Akita Railway opens Kemanai–Rikuchū-Hanawa, completing the private line.
• 192925 October: the government Hanawa Line is extended from Araya-Shinmachi to Tayama (following the 1926 Tairadate–Akasakata and 1927 Akasakata–Araya-Shinmachi openings).
• 193117 October: the state line is extended from Tayama to Rikuchū-Hanawa, joining the Akita Railway and completing a through route between Kōma and Ōdate.
• 19341 June: the Akita Railway is purchased, nationalised and merged into the Hanawa Line, completing an east–west railway across the Tōhoku region; five locomotives, six gasoline railcars, sixteen carriages and twenty-three freight wagons are inherited.
• 19591 March: diesel railcar (DMU) operation begins on the line.
• 197130 September: steam haulage ends with the withdrawal of the Class 8620 locomotives; the line is fully dieselised.
• 19841 February: all freight operations over the line are abolished.
• 19871 April: on the division and privatisation of Japanese National Railways, the Hanawa Line passes to JR East.
• 198813 March: Iwate-Matsuo Station is renamed Matsuo-Hachimantai and Ryūgamori Station is renamed Appi-Kōgen.
• 19951 December: Yuze Station is renamed Yuze-Onsen and Rikuchū-Hanawa Station is renamed Kazuno-Hanawa.
• 20021 December: with the Tōhoku Main Line's Morioka–Metoki section transferred to the IGR Iwate Galaxy Railway, Hanawa Line trains switch from through-running onto the Tōhoku Main Line to the Iwate Galaxy Railway line; the express 'Yoneshiro' is discontinued.
• 202213 August: heavy rain damages 54 sites between Kazuno-Hanawa and Ōdate, closing the section; full services resume on 14 May 2023.
• 202520 August: renewed heavy rain washes out track between Kazuno-Hanawa and Ōdate, closing the section; through services are restored on 26 September 2025.