The is a subway line in Japan owned and operated by Tokyo Metro. The line connects Wakà Âshi Station in Wakà Â, Saitama and Shin-Kiba Station in Kà Âtà Â, Tokyo. On maps, diagrams and signboards, the line is shown using the color "gold", and its stations are given numbers using the letter "Y".
The line was named after the Yà «rakuchà  business district in Chiyoda, Tokyo. The proper name as given in an annual report of the Ministry of Land, Infrastructure and Transport is . According to the Tokyo urban transportation plan, however, it is more complicated. The line number assigned to the section south from Kotake-Mukaihara to Shin-Kiba is Line 8, but that north of Kotake-Mukaihara to Wakà Âshi is Line 13, which indicates the section is a portion of Fukutoshin Line which shares the same number.
The Yà «rakuchà  Line runs generally northwest to southeast between Wakà Âshi Station in Saitama Prefecture and Shin-Kiba Station in Kà Âtà  Ward. Although it was originally planned as a bypass for the established Marunouchi Line through central Tokyo, it was also built to serve the developing wards of Itabashi, Nerima, Toshima, and Koto. The section between Wakà Âshi and Kotake-mukaihara shares tracks with its sister line, the Tokyo Metro Fukutoshin Line.
The Yà «rakuchà  Line has inter-running counterparts on its northern side, both of which are "major" Japanese private railway companies in Greater Tokyo. One is the Tobu Railway at Wakà Âshi, north to . The other is the Seibu Railway at with its bypass line Seibu Yà «rakuchà  Line connecting to its main Ikebukuro Line, through trains north to or .
According to the Tokyo Metropolitan Bureau of Transportation, as of June 2009 the Yà «rakuchà  Line is the fifth most crowded subway line in Tokyo, at its peak running at 173% capacity between Higashi-Ikebukuro and Gokokuji stations.
services ran on the Yà «rakuchà  Line between 14 June 2008 and 6 March 2010, operating twice hourly between Wakà Âshi and Shin-Kiba. Between Wakà Âshi and Ikebukuro, semi-express trains stopped only at Kotake-Mukaihara; between Ikebukuro and Shin-Kiba, trains stopped at all stations. The semi-express trains ran between rush hours during weekdays and more frequently on weekends and holidays. These services were abolished and replaced with local services on 6 March 2010.
The Yà «rakuchà  Line was first proposed in 1962 alongside the Chiyoda Line. Urban Transportation Council Report No. 6 (é½å¸Â交éÂÂ審è°ä¼ÂçÂÂç³第6å·) outlined it as a Line 10 (17.5 km) connecting âÂÂNakamurabashi - Mejiro - Iidabashi - Asakusabashi - KinshichoâÂÂ. On August 29 of the same year, the Ministry of Construction officially designated Line 10 as Line 8, approving a route connecting âÂÂNakamurabashi â Ekoda â Nishi-Ochiai â Shiinamachi â Mejiro â Edogawabashi â Iidabashi â Jimbocho â Sudacho â Higashi-Ryogoku Midoricho â KinshichoâÂÂ.
In 1968, it was later revised to run between Chikatetsu-narimasu Station in the northwest and Shintomichà  Station in the southeast; the extensions to Wakoshi and Shin-kiba were not confirmed at the time.
Line 8 was planned to serve areas that were not served by the Tokyo subway network such as Nerima and Koto Wards, while providing an adequate bypass for the overcrowding Marunouchi Line from Ikebukuro to Ginza-itchà Âme. This initial section began construction in 1970 and opened for revenue service on 30 October 1974 as the Yà «rakuchà  Line. In the late 1970s, the extensions towards Wakoshi and Shin-kiba were authorized. On 27 March 1980, the second section between Ginza-itchà Âme and Shintomichà  section opened, while the third section between Eidan-narimasu (now Chikatetsu-narimasu) and Ikebukuro opened on 24 June 1983.
Through services with the Seibu Yà «rakuchà  Line began on 1 October 1983 with the opening of the Kotake-Mukaihara â Shin-Sakuradai section. The northwestern extension to Wakà Âshi opened on 25 August 1987, allowing through service with the Tà Âbu Tà Âjà  Line. The final section from Shintomichà  to Shin-kiba opened on 8 June 1988, completing the current line.
On 18 March 1993, 07 series EMUs introduced. On 7 December 1994, the "Yà «rakuchà  New Line" (now the Fukutoshin Line) opened from Kotake-mukaihara to Ikebukuro. All trains on it made Ikebukuro their terminus and did not stop at Senkawa or Kanamechà Â. Through service from Shin-kiba or Ikebukuro (on the New Line) to on the Seibu Yà «rakuchà  Line began on that same day, with through operation to the Seibu Ikebukuro Line beyond Nerima beginning on 26 March 1998.
On 1 April 2004, the owner of the line changed from Teito Rapid Transit Authority (TRTA, Eidan) to Tokyo Metro due to the former's privatization. Women-only cars were introduced on 31 October 2005. 10000 series were introduced to the line on 1 September 2006.
On 3 May 2008, Limited Express "Bay Resort" (operated first from/to Odakyu Line) services began operating. On 14 June 2008, the Tokyo Metro Fukutoshin Line began service, and the Yà «rakuchà  New Line was absorbed into it. The Yà «rakuchà  Line shares tracks with the Fukutoshin Line between Wakà Âshi and Kotake-Mukaihara. Semi-Express services began running until they were abolished on 6 March 2010.
In October 2008, automatic train control was enabled on the Yà «rakuchà  Line. On 10 September 2012, 10-car 5050-4000 series sets entered revenue service on the Yà «rakuchà  Line, with inter-running through to the Tobu Tojo Line. Since 26 March 2017, Seibu operates the S-Train limited-stop express service between Toyosu and Tokorozawa on the Seibu Ikebukuro Line on weekday mornings and evenings.
On 6 August 2022, "Wanman" one-person operation began on the section between Kotake-Mukaihara and Shin-Kiba.
All types are operated as 10-car sets.
In 2021, plans were announced to branch the Yà «rakuchà  Line at Toyosu Station, traveling north for connecting with on the Tozai Line and Sumiyoshi Station on the Shinjuku Line and Hanzà Âmon Line. An additional two stations (Edagawa and Sengoku) would also be added in the Koto Ward serving the Sengoku and Toyo districts. Tentative names for the new stations were determined in August 2022. The branch line (nicknamed the Toyozumi Line according to official city documents) is intended to aid in redevelopment efforts in Koto Ward. As of 28 January 2022 the expected cost of construction is ÃÂ¥269 billion (2021). There are also plans for a spur branching off from the planned Tokyo Rinkai Subway line at Kachidoki to link up to the future Toyozumi Line (Yà «rakuchà  Line branch) platforms at Toyosu Station. The branch line is expected to be in service in the mid-2030s.
On 17 April 2025, Tokyo Metro and Tobu Railway announced plans to introduce through services via the Yà «rakuchà  Line branch and Hanzà Âmon Line to Tobu's Skytree, Isesaki, and Nikko lines.
A branch line from Toyosu Station has been planned since the early 1980s, heading north via Kameari Station (on the JÃ Âban Line) to Noda in northwest Chiba Prefecture.