"Future GPX Cyber Formula Sin" is the fifth and final installment in the "Future GPX Cyber Formula" franchise, set in a futuristic world where high-speed racing is revolutionized by advanced technology. The story takes place several years after the events of "Future GPX Cyber Formula Zero," focusing on Hayato Kazami, a former champion of the Cyber Formula racing circuit. Now retired, Hayato lives a quiet life with his wife, Kyoko, and their son, Shinjo. However, the peace is disrupted when a mysterious organization known as Ogre emerges, threatening the world with advanced AI-driven weapons and a new breed of Cyber Formula cars designed for destruction.

Ogre's leader, Kaga, seeks to dominate the racing world and beyond, using his superior technology to manipulate races and eliminate competitors. Hayato is drawn back into the fray when his former rival, Asurada, the AI system of his legendary racing car, is stolen by Ogre. Asurada is reprogrammed to serve Kaga's sinister agenda, forcing Hayato to confront his past and reclaim the machine he once trusted. Alongside his son, Shinjo, who inherits his father's passion for racing, Hayato embarks on a mission to stop Ogre and restore balance to the Cyber Formula world.

The narrative explores themes of legacy, redemption, and the ethical implications of advanced technology. Hayato's journey is not only a battle against external threats but also an internal struggle to reconcile his past achievements with his present responsibilities. Shinjo, as a young and inexperienced racer, represents the next generation, embodying hope and the potential for growth. The series also reintroduces familiar characters from previous installments, such as Kazami's former rivals and allies, who play pivotal roles in the fight against Ogre.

The racing sequences are central to the story, showcasing the evolution of Cyber Formula technology and the intense competition between drivers. The conflict escalates as Ogre's influence spreads, leading to high-stakes races and dramatic confrontations. The climax revolves around a final showdown between Hayato, Shinjo, and Kaga, with the fate of the Cyber Formula world hanging in the balance. The resolution emphasizes the enduring spirit of competition and the importance of human ingenuity over unchecked technological power.