The 1973 season of Japanese football.
Tanabe Pharmaceuticals was relegated, thereby becoming the first Japanese team to go straight back down one season after promotion.
Eidai promoted, Tanabe relegated.
Sumitomo, at the time based in Osaka, would move to Kashima, Ibaraki in 1975 and become today's Kashima Antlers.
Ibaraki Hitachi and Sumitomo promoted, Toyota Industries and Hagoromo Club relegated.