Kusatsu Line

The line was not built by the state but by the Kansai Railway, a private company that was extending its network westward from Nagoya toward the Kyoto–Osaka region. The first section, between Kusatsu and Mikumo, opened on 15 December 1889, with Ishibe and Mikumo stations; the route at this point formed the western end of the Kansai Railway's main line, reaching the Tōkaidō Main Line at Kusatsu.

On 19 February 1890 the railway was extended from Mikumo through to Tsuge, opening Fukakawa and Tsuge stations and completing the line in its present form. At Tsuge it met the rest of the Kansai Railway's route, giving the company a continuous link between Nagoya and the Kusatsu area on the shore of Lake Biwa.

The corridor's status changed in 1898. On 19 April that year the Kansai Railway reorganised its main line, redefining it to run between Nagoya and Kamo rather than between Nagoya and Kusatsu; as a result the Tsuge–Kusatsu stretch was demoted from main line to a branch. Kibukawa Station, which gave an interchange with the Ōmi Railway, was added on 29 December 1900.

Like most of Japan's larger private railways of the period, the Kansai Railway was taken into state ownership under the Railway Nationalization Act, being nationalised on 1 October 1907. The Tsuge–Kusatsu branch thereby passed to the national railways, and on 12 October 1909, when the government adopted formal line names, the section between Tsuge and Kusatsu was designated the Kusatsu Line.

For most of the twentieth century the line remained a steam- and later diesel-worked local route. Centralised traffic control (CTC) was commissioned in 1979, and the whole line was electrified at 1,500 V DC on 3 March 1980, allowing electric multiple units to take over services. Freight services on the line ceased in 1987. On 1 April 1987, with the division and privatisation of Japanese National Railways, the line passed to the newly formed West Japan Railway Company, which operates it today.

In the 2000s a plan was floated to add a new station, tentatively named Minami-Biwako, on the line near the Tōkaidō Shinkansen so that passengers could transfer between the two; construction began in May 2006 with completion planned for 2012. The scheme collapsed after the Ōtsu District Court ruled in September 2006 that Rittō City's issuing of bonds to fund the station was unlawful under local finance law, and the project was halted and then formally abandoned in October 2007. The Kusatsu Line continues to serve as a commuter and regional connector between the Kansai and Tōkaidō main lines.

• 188915 December: the Kansai Railway opens the first section, Kusatsu–Mikumo, together with Ishibe and Mikumo stations.
• 189019 February: the line is extended from Mikumo to Tsuge, opening Fukakawa and Tsuge stations and completing the line.
• 189819 April: the Kansai Railway redefines its main line to run Nagoya–Kamo instead of Nagoya–Kusatsu, and the Tsuge–Kusatsu section becomes a branch line.
• 190029 December: Kibukawa Station opens, giving an interchange with the Ōmi Railway.
• 19071 October: the Kansai Railway is nationalised under the Railway Nationalization Act; the branch passes to the national railways.
• 190912 October: the section between Tsuge and Kusatsu is formally designated the Kusatsu Line.
• 1979Centralised traffic control (CTC) signalling is commissioned on the line.
• 19803 March: the whole line is electrified at 1,500 V DC.
• 1987Freight services on the line cease; on 1 April, with the division and privatisation of Japanese National Railways, the line passes to the West Japan Railway Company (JR West).
• 2006May: construction begins on a proposed new station, tentatively named Minami-Biwako, for transfers to the Tōkaidō Shinkansen; in September the Ōtsu District Court rules Rittō City's funding bonds unlawful and the project is halted.
• 2007October: the Minami-Biwako station project is officially abandoned.