Dio Brando wants the Joestar fortune, and winning George Joestar's affection is his first move. Behind his dutiful behavior, he works to turn George against his own son, Jonathan, repeatedly outshining his foster brother to secure his position in the family.
Dio owes that position to a debt built on a misunderstanding. In 1868, George believed Dario Brando had rescued him and Jonathan after a carriage incident. Dario had actually intended to rob them, thinking they were dead. When Dario dies twelve years later, George takes in Dio to repay the supposed kindness.
Dio's provocations eventually drive Jonathan to fight him, and Jonathan wins. Years afterward, the pair seem to outsiders to have become close friends. That appearance conceals lingering distrust: when George falls ill, Jonathan suspects Dio is responsible, while Dio still has further schemes in reserve.
