Fukutoshin Line 副都心線

Overview
The Fukutoshin Line (Labelled as AF in the Map) is a line connecting the Secondary City centers of Tokyo (Shibuya, Shinjuku and Ikebukuro)

It has 1,067mm track gauge and operates 8 or 12 car Trains

The route is Electrified at 1500V

Starts at Daiba 台場 and ends at Akabane 赤羽, However some trains only operate between Ikebukuro/Shinjuku to Shinagawa during the morning rush hour

History
The line Opened between Ikebukuro and Shinagawa in 1904 as the Kyokai line.

The Kyokai line Extended to Akabane (Northern Termini) in 1963 and was electrified.In the same year, the line was renamed to the Fukutoshin Line.

The Fukutoshin Line extended to Daiba (Southern Termini) in 1999 and Limited stop services began.

The Line Abbreviation was changed from F to AF during the 2021 Naming Convention Reform