The 80 series electric trains were introduced in 1950 for long-distance semi-express trains on the Tokaido Main Line. They sported a green and orange paint scheme that was innovative for the time, and the following year, additional cars were fitted with a sleek design featuring two front windows. Nicknamed "Shonan Color" or "Shonan Style" after the 80 series' nickname, "Shonan Train," they had a major influence on future railcars. The 300 series, with its sleek bodywork perfected as part of the final all-golden car group, is particularly popular.
Around 1978, the 300 series was intensively deployed at Toyohashi Locomotive Depot on the Iida Line, where it remained in service until 1983.