This is the story of José Guadalupe Esparza and his three friends, and how they became one of the most successful regional music bands in México: Bronco. Together, they will fight the music industry establishment, escaping poverty and facing discrimination. After years of great and hard work, they managed to sell out their good-bye show at the Azteca Stadium in 1997, with over 30 million records sold all over the region. This is the story of Bronco: An Untamable Success.