Aizu Line

The line was built between 1927 and 1953 as the northern part of a planned through route connecting Aizu-Wakamatsu with Tokyo; the matching southern section was eventually realised as the Yagan Railway Aizu Kinugawa Line. The first segment, from Nishi-Wakamatsu to Kamimiyori (now Ashinomaki-Onsen), opened on 1 November 1927, a distance of 10.5 km. Construction then advanced south in stages over the following decades.

The line reached Yunokami (now Yunokami-Onsen) on 22 December 1932 and Aizu-Tajima on 27 December 1934. After the Pacific War, the route was pushed on south from Aizu-Tajima on 12 December 1947, and the final segment, to Aizu-Takinohara, opened on 8 November 1953, completing the line as the Aizu Line of Japanese National Railways (JNR). In December 1980, a realignment between Ashinomaki-Onsen and Yunokami-Onsen opened to clear the way for construction of the Ōkawa Dam.

On 9 October 1986 the line's terminus, Aizu-Takinohara, was renamed Aizu-Kōgen, and in the same year the Yagan Railway opened its Aizu Kinugawa Line, finally joining the Aizu Line to the railway network heading toward Tokyo via the Tōbu system. Despite this new link, the Aizu Line remained classed as an unprofitable secondary line, earmarked for transfer to local interests.

With the privatisation of JNR on 1 April 1987 the line passed first to the East Japan Railway Company (JR East). JR East's tenure was brief: on 16 July 1987 its first-class railway operations on the line ceased and the third-sector Aizu Railway, established by local governments, took over the 57.4-kilometre Nishi-Wakamatsu–Aizu-Kōgen line. The handover was accompanied by the renaming of nine stations along the route, among them Kamimiyori to Ashinomaki-Onsen, Yunokami to Yunokami-Onsen, and Itozawa to Nanatsugatake-Tozanguchi.

Electrification followed in 1990. On 12 October 1990 the Aizu-Tajima–Aizu-Kōgen section was electrified at 1,500 V DC, and Aizu Railway began mutual through-running with the Yagan Railway and Tōbu Railway, opening direct services off the line toward the Tokyo area. Japan Freight Railway ended its operations over the line on 1 April 1999. On 18 March 2006 the southern terminus Aizu-Kōgen was renamed once more, to Aizukōgen-Ozeguchi, its present name.

The "AIZU Mount Express" began running on 23 March 2002, and from 17 March 2012 it extended through onto the Tōbu Nikkō Line as far as Tōbu-Nikkō; days later, on 25 March 2012, the open-car observation excursion train "Ozatoro Tenbō Ressha Yu-meguri" began through-running to Kinugawa-Onsen on the Tōbu Kinugawa Line. A new limited express, the "Revaty Aizu" using Tōbu 500 series equipment, started in April 2017, and from 12 March 2022 it became the only electric train operating on the Aizu Line. Today the electrified southern part carries services that continue beyond Aizukōgen-Ozeguchi onto the Yagan Railway and Tōbu all the way to Tokyo, while the non-electrified northern part runs diesel trains that continue beyond Nishi-Wakamatsu to Aizu-Wakamatsu on the JR East Tadami Line.

21 stations tracked on the map, listed alphabetically. Select any to read its page.

• Aizu-Arakai会津荒海
• Aizu-Nagano会津長野
• Aizu-Sanson-Dojo会津山村道場
• Aizu-Shimogo会津下郷
• Aizu-Tajima会津田島
• Aizukogen-Ozeguchi会津高原尾瀬口
• Amayaあまや
• Ashinomaki-Onsen芦ノ牧温泉
• Ashinomaki-Onsen-Minami芦ノ牧温泉南
• Furusato-Koenふるさと公園
• Minami-Wakamatsu南若松
• Monden門田
• Nakaarai中荒井
• Nanatsugatake-Tozanguchi七ヶ岳登山口
• Nishi-Wakamatsu西若松
• Okawadamukoen大川ダム公園
• Tajimakoko-mae田島高校前
• Tonohetsuri塔のへつり
• Yagoshima弥五島
• Yoson-Koen養鱒公園
• Yunokami-Onsen湯野上温泉

• 19271 November: the first 10.5 km segment, Nishi-Wakamatsu–Kamimiyori (now Ashinomaki-Onsen), opens.
• 193222 December: the line is extended to Yunokami (now Yunokami-Onsen).
• 193427 December: the line is extended to Aizu-Tajima.
• 194712 December: the line is extended south from Aizu-Tajima.
• 19538 November: the final segment, to Aizu-Takinohara, opens, completing the JNR Aizu Line.
• 19801 December: a realignment between Ashinomaki-Onsen and Yunokami-Onsen opens, made for the construction of the Ōkawa Dam.
• 19869 October: the terminus Aizu-Takinohara is renamed Aizu-Kōgen; the same year the Yagan Railway opens its Aizu Kinugawa Line, connecting the line toward Tokyo.
• 19871 April: with the privatisation of JNR, the line passes to JR East.
• 198716 July: JR East's first-class operations on the line cease and the third-sector Aizu Railway takes over the 57.4 km Nishi-Wakamatsu–Aizu-Kōgen line; numerous stations are renamed (e.g. Kamimiyori→Ashinomaki-Onsen, Yunokami→Yunokami-Onsen).
• 199012 October: the Aizu-Tajima–Aizu-Kōgen section is electrified at 1,500 V DC, and mutual through-running with the Yagan Railway and Tōbu Railway begins.
• 19991 April: Japan Freight Railway (JR Freight) ends operations over the line.
• 200223 March: the 'AIZU Mount Express' service begins operating.
• 200618 March: the southern terminus Aizu-Kōgen is renamed Aizukōgen-Ozeguchi, its present name.
• 201217 March: the 'AIZU Mount Express' begins through-running to Tōbu-Nikkō on the Tōbu Nikkō Line. 25 March: the open-car observation train 'Ozatoro Tenbō Ressha Yu-meguri' begins through-running to Kinugawa-Onsen on the Tōbu Kinugawa Line.
• 2017April: the limited express 'Revaty Aizu', using Tōbu 500 series equipment, begins operating.
• 202212 March: the 'Revaty Aizu' becomes the only electric train operating on the Aizu Line.