Toei Shinjuku Line

The Toei Shinjuku Line is a rapid transit line in Tokyo and Chiba Prefecture, Japan, operated by the municipal Toei Subway. The line runs between in Ichikawa, Chiba in the east and in the west. At Shinjuku, most trains continue as through services to on the Keiō New Line, with some services continuing to in Sagamihara, Kanagawa via the Keiō Line and the Keiō Sagamihara Line.
On maps and signboards, the line is shown in the color leaf green. Stations carry the letter "S" followed by a two-digit number inside a lime green circle.
In fiscal year 2023, the Shinjuku Line was Toei's third most profitable line, earning in surplus. It served 704,235 passengers on average per day, the second highest in the Toei network.

Basic data

Unlike all other Tokyo subway lines, which were built to or gauges, the Shinjuku Line was built with a track gauge of to allow through operations onto the Keiō network. The line was planned as Line 10 according to reports of a committee of the former Ministry of Transportation; thus the rarely used official name of the line is the "Number 10 Shinjuku Line".
According to the Tokyo Metropolitan Bureau of Transportation, as of June 2009 the Shinjuku Line was the third most crowded subway line in Tokyo, at its peak running at 181% capacity between Nishi-ōjima and Sumiyoshi stations.
It is the only Toei line to run outside Tokyo, and one of only two Tokyo subway lines to run into Chiba Prefecture, the other being the Tokyo Metro Tozai Line. The Tokyo Metro Yūrakuchō Line, the Tokyo Metro Fukutoshin Line and the Tokyo Metro Tozai Line are the only other subway lines to run beyond Tokyo, with the shared northern terminus of the first two at Wakōshi Station in Saitama Prefecture, and the eastern terminus of the Tozai Line being at Nishi-Funabashi Station in Chiba Prefecture. However, all lines that have through services contain at least one route beyond Tokyo.

Express trains stop at stations marked with a circle, while local trains make all stops.
Express trains run between Motoyawata Station and Hashimoto Station on the Keiō Sagamihara Line via the Keio Main Line and Keio New Line. Express trains only run during peak hours; westbound in the mornings and eastbound in the evenings.
On weekends and holidays, two trains run through to Takaosanguchi Station on the Keiō Takao Line and one runs through to Tama-Dōbutsukōen Station on the Keiō Dōbutsuen Line.

The Toei Shinjuku Line is served by the following types of 10-car EMUs. Until 11 August 2022, the line was also served by 8-car trains.

21 December 1978: Iwamotochō - Higashi-ōjima section opens.
16 March 1980: Shinjuku - Iwamotochō section opens; through service onto Keiō lines begins.
23 December 1983: Higashi-ōjima - Funabori section opens.
14 September 1986: Funabori - Shinozaki section opens.
19 March 1989: Shinozaki - Motoyawata section opens, entire line completed.