Higashiyama Main Line

The operating company is one of the oldest names in Japanese tramways. Okayama Electric Tramway was established on 21 May 1910, and — alongside the Nagasaki Electric Tramway — is one of the rare Meiji-era Japanese railway companies that has never once changed its corporate name since its founding. It opened its first tram service in 1912 and today is a core member of the Ryōbi Group, with Ryōbi Holdings as its principal shareholder.

The line opened in two stages in 1912. On 5 May 1912 the first section ran from Okayama-Ekimae to Shiroshita, and on 1 June 1912 the line was extended onward from Shiroshita to Saidaijichō. The route reached its present eastern terminus more than a decade later, on 9 July 1923, when the section from Saidaijichō to Higashiyama opened, completing the 3.1 km line as it exists today.

For most of the twentieth century the line settled into its role as the backbone of Okayama's tram network, sharing its inner-city tracks with the Seinai Line, which branches off toward Seinaisen-Shimizu. As Japanese tramways elsewhere were dismantled in the post-war decades, Okaden retained and modernised its compact system, and the Higashiyama Main Line remained the principal artery linking the station forecourt with the eastern suburbs.

In the twenty-first century the line became a showcase for modern low-floor trams. Okaden's earlier cars carried two-digit type numbers up to the 9200-series "MOMO", a partly low-floor light-rail vehicle introduced in 2002; from the three-digit "MOMO²" of 2011 the company adopted a new numbering scheme. The MOMO design later lent its concept and name to vehicles on Okaden's subsidiary, the Wakayama Electric Railway — the same company famous for its feline stationmaster, Tama — although Tama herself served at Kishi Station in Wakayama and never on the Okayama line. Several stops were also renamed to reflect new landmarks: Nishigawa became Nishigawa-Ryokudō-Kōen in 2008, the eastern terminus Higashiyama was renamed Higashiyama·Okaden Museum in 2017, and Saidaijichō became Saidaijichō·Okayama Geijutsu Sōzō Gekijō Halenowa-mae in 2023.

The line has continued to evolve in recent years. In January 2018 Okaden announced a tie-up with the British children's animation "Chuggington", and from 16 March 2019 a Chuggington-themed sightseeing tram, based on the MOMO design, began running between Okayama-Ekimae and Higashiyama·Okaden Museum. On 15 September 2025 a tram collided with a route bus at the Omotechō intersection and derailed, injuring two people; service resumed the following day. Looking ahead, the company plans to extend the line about 100 metres in the spring of 2027 so that trams run directly into the east-exit plaza of Okayama Station.

• 191021 May: Okayama Electric Tramway is established — a company that, with the Nagasaki Electric Tramway, has never changed its name since founding.
• 19125 May: the first section of the Higashiyama Main Line opens between Okayama-Ekimae and Shiroshita.
• 19121 June: the line is extended from Shiroshita to Saidaijichō.
• 19239 July: the section from Saidaijichō to Higashiyama opens, completing the 3.1 km line to its present eastern terminus.
• 2002The 9200-series 'MOMO' partly low-floor light-rail vehicle is introduced; it is the last Okaden car to carry a two-digit-style type number before the new scheme.
• 20081 April: Nishigawa stop is renamed Nishigawa-Ryokudō-Kōen.
• 2011The 'MOMO²' low-floor tram enters service; from this car Okaden adopts three-digit type numbers.
• 20171 April: the eastern terminus Higashiyama is renamed Higashiyama·Okaden Museum.
• 201812 January: Okaden announces a tie-up with the British animation 'Chuggington', a sightseeing tram to begin running within the year.
• 201916 March: the Chuggington-themed sightseeing tram begins running between Okayama-Ekimae and Higashiyama·Okaden Museum.
• 202327 April: Saidaijichō stop is renamed Saidaijichō·Okayama Geijutsu Sōzō Gekijō Halenowa-mae.
• 202515 September: a tram collides with a route bus at the Omotechō intersection and derails, injuring two; service resumes the next day.
• 2027Spring (planned): the line is to be extended about 100 m from Okayama-Ekimae into the east-exit plaza of Okayama Station.