In the American Old West, the stage is set for the planet's most extraordinary race. Thousands of competitors gather in San Diego, ready to embark on a journey of over six thousand kilometers, with a fifty-million-dollar prize as the ultimate reward. As the era of horses comes to an end, racers can use any type of vehicle. They must navigate harsh conditions and traverse uncharted desert landscapes, sometimes traveling up to one hundred kilometers daily. The Steel Ball Run is an unparalleled contest.
Johnny Joestar, a young former horse racer now wheelchair-bound, arrives in San Diego just as the race begins. Here, he encounters Gyro Zeppeli, a racer who carries two steel spheres instead of a weapon. Johnny witnesses Gyro using one of these spheres to create a supernatural effect, causing a man in a standoff to turn his own gun against himself. Amidst the chaos, Johnny accidentally touches the steel ball, feeling energy surge through his legs, allowing him to stand after two years of being confined to a wheelchair. Driven by the desire to unravel the mystery behind the steel balls, Johnny decides to join the race, embarking on a bizarre adventure across America during the Steel Ball Run.