The is the tentative name for a planned underground

heavy rail Various terms are used for passenger railway lines and equipment; the usage of these terms differs substantially between areas: Rapid transit A rapid transit system is an electric railway characterized by high speed (~) and rapid acceleratio ...

line which will run north-south between

Tokyo Station Tōkyō Station (, ) is a major railway station in Chiyoda, Tokyo, Japan. The original station is located in Chiyoda's Marunouchi business district near the Tokyo Imperial Palace, Imperial Palace grounds. The newer Eastern extension is not far ...

and the Ariake district along

Tokyo Bay is a bay located in the southern Kantō region of Japan spanning the coasts of Tokyo, Kanagawa Prefecture, and Chiba Prefecture, on the southern coast of the island of Honshu. Tokyo Bay is connected to the Pacific Ocean by the Uraga Channel. Th ...

. As of 25 November 2022, the projected completion date is in the 2040s.

Background

Plans to construct a new subway line connecting Tokyo Station to the Tokyo Bay area had been in discussion since 2015 as

Tokyo Tokyo, officially the Tokyo Metropolis, is the capital of Japan, capital and List of cities in Japan, most populous city in Japan. With a population of over 14 million in the city proper in 2023, it is List of largest cities, one of the most ...

was undergoing preparations to host the

2020 Summer Olympics The officially the and officially branded as were an international multi-sport event that was held from 23 July to 8 August 2021 in Tokyo, Japan, with some of the preliminary sporting events beginning on 21 July 2021. Tokyo ...

. However, on 25 November 2022, Tokyo governor

Yuriko Koike Yuriko Koike (小池百合子, Koike Yuriko; born 15 July 1952) is a Japanese politician who has served as the Governor of Tokyo since 2016. Previously, she was also served as a member of the House of Councillors from 1992 to 1993, a member o ...

revealed concrete plans to construct the subway line. The line will be around long and will feature 7 stations. Overall, the cost is expected to be and is projected to open in the 2040s. There are plans to run through services with the

Rinkai Line The is a railway line in Tokyo, Japan. It is the only line operated by the third-sector company Tokyo Waterfront Area Rapid Transit. It connects central Tokyo to the artificial islands of Aomi and Odaiba. The line is served by some trains on ...

and the

Tsukuba Express The , or TX, is a Japanese railway line operated by the Third-sector railway, third-sector company Metropolitan Intercity Railway Company, which links Akihabara Station in Chiyoda, Tokyo and Tsukuba Station in Tsukuba, Ibaraki. The route was ...

along with a possible integration with the JR Haneda Airport Access Line. There are also plans to have a spur connection to the Toyozumi Line at

Toyosu is neighborhood in Kōtō, Tokyo. Toyosu has six numbered Japanese addressing system, ''chome'' ("blocks"). It is the location of the wholesale Toyosu Market, which took the role of the Tsukiji fish market after it became solely a tourist attrac ...

Station. The rationale for building the line is due to the development of Tokyo Bay and the integration of leftover facilities from the 2020 Summer Olympics such as the athlete's village (which have since been remarketed as

condominium A condominium (or condo for short) is an ownership regime in which a building (or group of buildings) is divided into multiple units that are either each separately owned, or owned in common with exclusive rights of occupation by individual own ...

s) and competitor venues. In addition, the island on which the former athlete's village is located, Harumi, remains without a railway connection. Construction is projected to begin in the 2030s. As of November 2022, the company in charge of construction has not been decided.

JR East

Upon completion of the line, JR East plans to build a connection from the Haneda Airport Access Line to the Tokyo Rinkai Subway Line.

Rinkai Line

A connection to the

from the southern terminus at Ariake is also being considered.

Toyozumi Line

There are also plans for a spur branching off from Kachidoki to link up to the future Toyozumi Line ( Yurakucho Line branch) platforms at

Station.

Tsukuba Express

A northern extension of the Rinkai Subway Line to connect to the

Akihabara Station is an interchange railway station in Chiyoda, Tokyo, Japan. It is at the center of the Akihabara shopping district specializing in electronic goods. Lines Akihabara Station is served by the following lines. JR East: * Tōhoku Main Line ** Ke ...

was also discussed by the

Tokyo Metropolitan Government The is the government of the Tokyo, Tokyo Metropolis. One of the 47 Prefectures of Japan, prefectures of Japan, the government consists of a popularly elected governor and assembly. The Tokyo Metropolitan Government Building, headquarters build ...

. File:Tokyo 2020 Olympic Games- Athletes Village (HARUMI FLAG) - 51213927292.jpg, Harumi, the former Athlete's Village of the 2020 Summer Olympics

Stations

All station names are provisional.

References

{{Reflist

External links

Project summary (in Japanese)

Official promotional material (in Japanese)
Proposed rail infrastructure in Japan Proposed railway lines in Japan Railway lines in Tokyo