When the Kosei Line was opened, there appeared the model numbers 700's of the JNR/JR Suburban Train Series 113, which have measures such as semiautomatic doors for cool regions; these have been the major cars operated on the Kosei Line and are operated comprised of four to eight cars along with the cars of the model numbers 2700's, which appeared for the electrification of the Kusatsu Line.
湖西線開業時に半自動扉などの寒地対策車をした113系700番台が登場し、以来現在まで湖西線電車の主力であり、草津線電化用に登場した2700番台を交えて4～8両編成で運用されている。