The JNR/JR Suburban Train Series 113 (mainly the 700 and 2700 series cars) were introduced in the opening of Kosei Line and the electrification of the Kusatsu Line; the JNR/JR Suburban Train Series 113 is the major electric train operated on the Kusatsu Line.
国鉄113系電車-湖西線開業・草津線電化時に投入された700・2700代車を中心に使用され、草津線電車の主力。