In 2001, two years after the events of Diamond Is Unbreakable, Koichi Hirose is sent to Italy by Jotaro Kujo, who commissions him to investigate a person known as Haruno Shiobana, whose real name is later revealed as Giorno Giovanna, son of Dio Brando. The story then follows Giorno in his goal of reaching the top of the "Passione" mob group in which his goal is to turn them into a band of upright thieves.
