The was a Japanese DC electric multiple unit (EMU) train type operated on limited express services by Japanese National Railways (JNR) from 1959 until 1980.
The 157 series EMUs were first introduced by JNR on Nikkà  semi express services between and on 22 September 1959 to counter competition from the private company Tobu Railway, which also operated trains to Nikkà Â. They were also used on Chusenji services between and Nikkà Â, and Nasuno services between and .
157 series EMUs were also introduced on seasonal Hibiki services on the Tokaido Main Line from 21 November 1959, and were later used on Amagi and Soyokaze services.
Initially painted in the JNR livery of beige ("Cream No. 4") and crimson ("Red No. 11"), the red colour was later changed to a slightly darker shade ("Red No. 2") when the sets were modified with the addition of air-conditioning.
The 157 series fleet included a dedicated imperial train car, built by Kawasaki Sharyo (present-day Kawasaki Heavy Industries) and delivered in June 1960. Numbered KuRo 157-1, the car could be inserted into 157 series formations for use on imperial train workings. One end had a gangwayed driving cab based on the 153 series EMU design, although the car was normally sandwiched in the middle of a 157 series formation, and was only very rarely used with the driving cab leading. In 1979, the car was modified for use in conjunction with 183 series EMUs, with the first official working on 2 July 1980. From March 1985, it was repainted in cream with a green stripe for use in conjunction with 185 series EMUs.
The last official operation of the car was on 8 September 1993.
Following retirement, the KuRo 157-1 car remained in storage at Tamachi Depot for many years, but was moved to Tokyo General Rolling Stock Centre in the early hours of 2 December 2012.
The first 157 series set was delivered in August 1959, and entered service on Nikkà  semi express services between Tokyo and Nikkà  from 22 September 1959. Air-conditioning was added to the trains from 1962.
With the exception of the special imperial train car KuRo 157-1, the entire fleet of 157 series trains was withdrawn by 1980.
The individual car histories are as follows.