"Jujutsu Kaisen: Kaigyoku・Gyokusetsu" is a two-part anime film that serves as a prequel to the main "Jujutsu Kaisen" series, focusing on the backstory of Satoru Gojo and Suguru Geto during their time as students at Tokyo Jujutsu High. The narrative explores their friendship, ideological differences, and the events that shape their futures as powerful jujutsu sorcerers.

The story begins with Satoru Gojo and Suguru Geto, two exceptionally talented students, tasked with protecting Riko Amanai, a young girl known as the "Star Plasma Vessel." Riko is destined to merge with Master Tengen, an immortal being who maintains the balance of the jujutsu world. The merger is essential to prevent Tengen from evolving into a chaotic force that could destabilize the world. However, a shadowy organization known as the Time Vessel Association opposes the merger, seeking to eliminate Riko to disrupt the balance and achieve their own goals.

As Gojo and Geto escort Riko, they face numerous threats from assassins and curse users aligned with the Time Vessel Association. The duo’s contrasting personalities and philosophies become increasingly apparent. Gojo, confident and carefree, believes in his unparalleled strength and the importance of individual freedom. Geto, more introspective and idealistic, struggles with the moral implications of their mission, questioning the ethics of sacrificing Riko for the greater good.

The tension escalates when Toji Fushiguro, a non-sorcerer with immense physical prowess and cursed tools, is hired to kill Riko. Toji’s intervention leads to a brutal confrontation, testing Gojo and Geto’s abilities and resolve. The aftermath of this battle has profound consequences, particularly for Gojo, who undergoes a transformative experience that solidifies his status as the strongest sorcerer.

The film delves into the emotional and psychological toll of their mission, culminating in a tragic turn of events that fractures Gojo and Geto’s friendship. Riko’s fate and the moral dilemmas surrounding her role as the Star Plasma Vessel force Geto to confront his disillusionment with the jujutsu world. This disillusionment sows the seeds for his eventual descent into darkness, setting the stage for his role as a major antagonist in the main series.

"Jujutsu Kaisen: Kaigyoku・Gyokusetsu" provides critical context for understanding the dynamics between Gojo and Geto, their shared history, and the ideological rift that defines their later actions. The film enriches the overarching narrative of "Jujutsu Kaisen" by exploring themes of duty, morality, and the cost of power, while offering a deeper look into the formative experiences of two of the series’ most pivotal characters.