Pre-WWII

The 83 km (52 mi) line from Shinjuku to Odawara opened for service on 1 April 1927. Unlike the Odawara line, rarely were pre-World War II Japanese private railways constructed with double-track and fully electrified from the first day of operation. Two years later, on 1 April 1929, the Enoshima Line was added.

The original full name of the railroad was Odawara Express Railway Company, Ltd. (小田原急行鉄道株式会社, Odawara Kyūkō Tetsudō kabushiki gaisha),^[1] but this was often shortened to Odawara Kyūkō (小田原急行, "Odawara Express"). The abbreviation Odakyu was made popular by the title song of the 1929 movie Tōkyō kōshinkyoku and eventually became the official name of the railroad on March 1, 1941.^{[2][page needed]}

On 1 May 1942, Odakyu merged with the Tokyo-Yokohama Electric Railway company (now Tokyu Corporation), which controlled all private railway services west and south of Tokyo by the end of World War II.

Post-WWII

The company regained its independence on June 1, 1948, and it obtained a large amount of Hakone Tozan Railway stocks, instead of separating Keio Inokashira Line for Keio Corporation. Odakyu restarted Non-stop Limited Express service between Shinjuku and Odawara in 1948. In 1950, Odakyu trains ran through to Hakone-Yumoto on Hakone Tozan Line. Odakyu uses 1,067 mm (3 ft 6 in) narrow gauge tracks, but the Hakone Tozan Railway is 1,435 mm (4 ft 8+1⁄2 in) standard gauge, so one track of the section from Odawara to Hakone-Yumoto (6.1 km (3.8 mi)) was changed to a dual gauge system. Odakyu operated the first Romancecar (1710 series) limited express in 1951.

After the 1950s, due to rapid Japanese economic growth, Odakyu was faced with an explosive increase of population along with its lines. Commuter passengers had to use very crowded trains every morning, and complained strongly with the delay of improvements from the railway company. Odakyu began construction on the - "Shinjuku Station Great Improvement Project" setting 5 lines and 10 platforms long enough for 10 standard commuter cars with service on the Chiyoda Line, among others. Plans for a four-track system in 1964 were prevented by residents of Setagaya Ward in Tokyo, as such the system remains uncompleted. The Setagaya Residents' opposition set the stage for a long-term and remarkable case in the courts and legislature. Odakyu could not take main part of transport from Tama New Town Area, though Odakyu started the operation of Tama Line in 1974. To serve its Mukōgaoka-Yūen Amusement Park, Odakyu operated the Mukōgaoka-Yūen Monorail Line between Mukōgaoka-Yūen and Mukōgaoka-Yūen-Seimon (1.1 km (0.68 mi), 2 stations) beginning in 1966 using a Lockheed Corporation style monorail system; the system was closed in 2001 when the amusement park was shut down.

Post-millennium

Since 2000, Odakyū has been adding track in both directions from Izumi-Tamagawa Station, on Tama River, the border station of Tokyo, to just outside Setagaya-Daita Station for expanding the availability of express trains, especially for morning commuter service. The lines between Setagaya-Daita and Higashi-Kitazawa Station are still under construction, however. Odakyu announced that the bottle-neck will be resolved by 2013.

All of its lines are double- or quadruple-tracked within Tokyo Metropolis as of March 2018, a project first decided in December 1964 but due to NIMBY land acquisition difficulties, complex and expensive workarounds were constructed and finished, taking a half century. The main or Odawara Line acts as a bypass route for the Tōkaidō Main Line from Tokyo to western Kanagawa. The Romancecar 3000 series "SE" was tested at speeds of up to 145 km/h (90 mph) in 1957, achieving a world record for narrow gauge 1,067 mm (3 ft 6 in) lines at the time. These tests also provided important data on high-speed electric multiple units (EMU), which Japanese National Railways (JNR) used for its limited express EMUs, 151 series, and 0 Series Shinkansen introduced in the early 1960s.

Odakyu celebrated its 80th anniversary in April 2007. The 50th anniversary of the Romancecar was celebrated in September 2007.

Station numbers were introduced to all Odakyū Line stations in 2014, with stations numbered using the prefix "OH".^[3][4]

Odakyu are the current shirt sponsors of football club Machida Zelvia.

On 6 August 2021, a mass stabbing incident occurred on one of its commuter services when a man stabbed nine passengers, seriously injuring a woman before trying to ignite a fire on the compartment. The man escaped and was arrested hours later.^[5]

Shinjuku Station routes

Commuter service is shown on each line's page.

• Mt. Fuji trains run on the connecting branch line just before Shin-Matsuda from Shinjuku and stops at Matsuda on the Gotemba Line. Matsuda and Shin-Matsuda are treated as the same station.
• Home Way trains run from Shinjuku every evening after 18:00. There is no service to Shinjuku.

Tokyo Metro routes

Commuter services are shown on each line's page.

• At Yoyogi-Uehara, all trains pause, but there is no service for passengers; Odakyū and Tokyo Metro change their operating staff at the station.
• On weekday mornings, Metro Sagami trains run once from Hon-Atsugi to Kita-Senju.
• On weekday evenings, Metro Homeway trains run twice from Hon-Atsugi to Kita-Senju and once from Ōtemachi to Hon-Atsugi.
• On weekends and holidays, Metro Hakone trains run between Kita-Senju and Hakone-Yumoto four times; Metro Sagami (once in the morning) and Metro Homeway (once in the evening) trains also run between Kita-Senju and Hon-Atsugi.
• Once or twice per month, Metro Sagami and Metro Homeway become Bay Resort trains, traveling between Shin-Kiba and Hon-Atsugi. They travel to/from the Tokyo Metro Yūrakuchō and Chiyoda lines.

Legend

Romancecar sets

• 30000 series "EXE/EXEalpha" (introduced 1996)
• 60000 series "MSE" (introduced 2008)
• 70000 series "GSE" (introduced 2018)

Former

• 3000 series "SE" (1957–1991)
• 3100 series "NSE" (1963–2000)
• 7000 series "LSE" (1980–2018)
• 10000 series "HiSE" (1987–2012)
• 20000 series "RSE" (1991–2012)
• 50000 series "VSE" (2005–2022)

• 7000 series "LSE"
• 30000 series "EXEalpha"
• 50000 series "VSE"
• 60000 series "MSE
• 70000 series "GSE"

Commuter sets

Current

• 1000 series (introduced 1988)
• 2000 series (introduced 1995)
• 3000 series (introduced 2002)
• 4000 series (introduced 2007)
• 5000 series (introduced 2020)
• 8000 series (introduced 1983)

Former

• 5000 series (1969–2012)
• 9000 series (1972–2006)

• 8000 series
• 9000 series
• 1000 series
• 2000 series
• 3000 series
• 4000 series
• 5000 series