Ino Line

The line was built by the first Tosa Electric Railway company, which opened the first section on 2 May 1904 as the "Honchō Line" — a single track between Horizume and Noridashi (the present-day Gurando-dōri stop). It was extended westward in stages: from Noridashi to Kagamigawabashi on 9 October 1906, from Kagamigawabashi to Kōnai on 16 September 1907, and from Edagawa to Ino on 7 November 1907.

The remaining gaps were closed the following year. The Kōnai–Edagawa section opened on 20 February 1908, and on 31 October 1908 the Geka (now Hōeichō)–Horizume section opened, completing the line throughout. Double-tracking of the busy central section then began: the Horizume–Noridashi stretch was doubled by 20 February 1909, and Noridashi–Honchōsuji-gochōme (now Kamimachi-gochōme) by 22 May 1909.

The operating company changed repeatedly through the first half of the twentieth century. Through a merger with Tosa Suiryoku Denki and a change of name, the line passed to Tosa Denki on 1 August 1922; it became part of Tosa Kōtsū on 12 July 1941 following a merger with Kōchi Railway and Tosa Bus; and on 3 June 1948, after a merger with Nankai Tan'atsuki, it came under the second Tosa Electric Railway company. Double-tracking continued in parallel, reaching Hotarubashi by 17 April 1950 and Kagamigawabashi by 1 October 1958, while a new stop, Narutani, was added on 11 June 1955.

Various route and stop changes followed in the post-war decades. In 1960 the track between Miyano-oku and Ujidanchi-mae was relocated and the Kōnaizaka tunnel removed, and the Kitayamaguchi and Shiozaki stops were merged into a new Kitayama stop. Several stops were closed to speed up services — Asahimachi-nichōme in 1967, and Nakanohashidōri and Kamimachi-sanchōme in 1977 — and on 18 February 1979 two trams, cars 611 and 618, collided head-on between Kōnai and Ujidanchi-mae.

The modern era brought safety and operational reforms. On 1 October 2014 the second Tosa Electric Railway was succeeded by Tosaden Kōtsū, formed through the management integration of the railway with Kōchi-ken Kōtsū and Tosaden Dream Service. A serious incident occurred at Asakura on 17 November 2016, and again on 25 March 2019, when an Ino-bound car departed without receiving the single-line token; in response the company stationed staff to hand over tokens at Asakura and at the Yashiro signal point.

On 9 January 2021 the token exchange at the Yashiro passing place ceased altogether, and the tablet shape on the Asakura–Ino section was standardised. Finally, on 10 April 2023 the safety system on the Asakura–Ino section was changed from token (tablet) working to special automatic block, ending the last token-operated tramway section in Japan; the stationmaster post that had been reinstated at Asakura was abolished at the end of May, returning the stop to unstaffed operation.

• 19042 May: the first Tosa Electric Railway opens the first section as the 'Honchō Line' — single track from Horizume to Noridashi (now Gurando-dōri).
• 19069 October: the Noridashi–Kagamigawabashi section opens as single track.
• 190716 September: the Kagamigawabashi–Kōnai section opens; 7 November: the Edagawa–Ino section opens.
• 190820 February: the Kōnai–Edagawa section opens; 31 October: the Geka (now Hōeichō)–Horizume section opens, completing the line throughout.
• 1909Double-tracking of the central section is completed: Horizume–Noridashi by 20 February and Noridashi–Honchōsuji-gochōme (now Kamimachi-gochōme) by 22 May.
• 19221 August: through a merger with Tosa Suiryoku Denki and a name change, the line becomes part of Tosa Denki.
• 194112 July: following a merger with Kōchi Railway and Tosa Bus, the line becomes part of Tosa Kōtsū.
• 19483 June: after a merger with Nankai Tan'atsuki, the line passes to the second Tosa Electric Railway company.
• 19581 October: double-tracking of the Hotarubashi–Kagamigawabashi section is completed (Honchōsuji-gochōme–Hotarubashi having been doubled by 1950).
• 1960Track between Miyano-oku and Ujidanchi-mae is relocated and the Kōnaizaka tunnel removed; the Kitayamaguchi and Shiozaki stops are merged into a new Kitayama stop.
• 197720 June: the Nakanohashidōri and Kamimachi-sanchōme stops are closed to speed up services (Asahimachi-nichōme having closed in 1967).
• 197918 February: trams 611 and 618 collide head-on between Kōnai and Ujidanchi-mae.
• 20141 October: the second Tosa Electric Railway is succeeded by Tosaden Kōtsū, formed by the management integration of the railway with Kōchi-ken Kōtsū and Tosaden Dream Service.
• 201925 March: a serious incident occurs at Asakura when an Ino-bound car departs without receiving the single-line token (a similar incident had occurred on 17 November 2016); staff are thereafter stationed to hand over tokens at Asakura and the Yashiro signal point.
• 202310 April: the safety system on the Asakura–Ino section is changed from token (tablet) working to special automatic block, ending the last token-operated tramway section in Japan; the Asakura stationmaster post is abolished at the end of May and the stop returns to unstaffed operation.