Part 4: Diamond is Unbreakable

Part 4 of Jojo's Bizarre Adventure (subtitled Diamond is Unbreakable,) is preceded by Part 3: Stardust Crusaders and succeeded by Part 5: Golden Wind. Josuke Higashikata is the main JoJo of this part and Yoshikage Kira serves as the main antagonist. Enemy Stand Users serve as the villainous faction for this part.

Official Description
In Part 4, set in 1999 in the fictional town of Morioh, high-schooler Josuke Higashikata and his friends seek out the Arrow, which has the power to give Stand abilities, as well as the serial-killer Yoshikage Kira.

Plot Summary
The fourth part Diamond is Unbreakable is set in the fictional town of Morioh, Japan, in 1999. It follows Joseph's illegitimate son Josuke Higashikata as he meets friends and enemies among a host of new Stand users within the population of Morioh created with the Bow and Arrow, two items which gave DIO his Stand. He, Okuyasu Nijimura, Koichi Hirose, Jotaro Kujo, and Rohan Kishibe eventually chase the serial killer Yoshikage Kira.