Jotaro Kujo is the grandson of Joseph Joestar, the previous JoJo's protagonist. One day, Jotaro severely injured four gang members, which caused him to believe he was possessed by an evil spirit, since he'd never shown the strength to do that before. After he turned himself to the police, his grandfather came and explained to him what was going on. Dio, the vampire adoptive brother of Joseph's grandfather Jonathan, has reawakened and gained a Stand, a manifestation of his personality that he can summon, and since Dio's head is attached to Jonathan's body, the rest of the Joestar bloodline awakened Stands on their own. However, Jotaro's mother also awakened a Stand, which was slowly killing her due to her inability to control it. This led to Jotaro, Joseph, and some other Stand users to travel to Egypt, defeat Dio, and save Jotaro's mom.
Master Stragetist: Due to his intelligence, Jotaro is a master stragetist. he is able to plant a magnet on Dio by tricking him to know where he was, and was able to Enyaba despite being cautious to not mess it up.
Star Platinum: Jotaro's Stand, Star Platinum, is a manifestation of his personality that he can summon to fight for him. Like all Stands, it can only be seen by another Stand user. It is one of the strongest and most versatile Stands in the series, despite its simple power set.
Superhuman Strength: Star Platinum has immense physical strength. It can lift a jeep carrying four people with one hand, rip apart steel bars, and shatter several giant diamond-hard teeth with its punches.
Superhuman Speed: Star Platinum is considered faster than light, being able to throw thousands of punches in seconds and catching point-blank bullets.
Precision: Star Platinum's precision is amazing, being able to remove objects embedded in people's skulls without ill effects and catching bullets in its fingers.
Self-Preservation: Star Platinum's main instinct is to protect Jotaro from harm, and it will shield Jotaro from harm at all costs.
Enhanced Eyesight: Star Platinum has eagle-like eyesight. It's able to see stuff from four kilometers away, and follow card shuffles performed by professional gamblers.
Star Finger: Star Platinum can extend its middle and index fingers at opponents to stab them from far away.
Time Stop: During the final battle with Dio, Star Platinum awakened the ability to stop time for five seconds, with only Jotaro and Star Platinum being able to move during the stopped time. The time stop reaches out into space, but it also stops Jotaro's heart when it's in use, so he can't spam it.