The Steel Ball Run is a high-stakes race that spans over 6,000 kilometers from San Diego, with a grand prize of $50 million. Contestants are allowed to use any vehicle they choose, reflecting the era's shift away from horses. Johnny Joestar, a former horse racer with a mobility issue, attends the starting event in San Diego and meets Gyro Zeppeli, a skilled racer with a unique setup of two steel balls. After witnessing Gyro use one of his steel balls, Johnny touches it and gains the ability to stand, leading him to join the competition and uncover the secrets of the steel balls.