The 207 series (207系) or 207–900 series (207系900番台) was a commuter electric multiple unit (EMU) train type introduced in 1986 by Japanese National Railways (JNR) and operated by East Japan Railway Company (JR East) on through services between the Joban Line and Tokyo Metro Chiyoda Line. Only one 10-car set was built, which was withdrawn in December 2009.