Sixty-eight years after the devastating Culling Games, Tokyo has become the world’s capital of cursed energy, a place where sorcery and futuristic technology have begun to merge. The age of legendary heroes like Yuji Itadori has long passed, and a new, unprecedented threat has descended from the stars. An alien race known as the Simurians arrives on Earth aboard a massive spaceship, seeking refuge. These beings possess their own unique form of cursed energy, and their sudden appearance throws the fragile peace of the jujutsu world into chaos.

The story centers on siblings Yuka and Tsurugi Okkotsu, the grandchildren of the powerful sorcerers Yuta Okkotsu and Maki Zenin. While Tsurugi was born with no cursed energy and fights using cursed tools, Yuka is a powerful sorcerer in her own right, though she is tragically weakened by a terminal illness. Their mission to investigate a wave of kidnappings leads them to Maru, a young Simurian diplomat sent to Earth to test the possibility of coexistence. Together, they uncover a black market where children are sold as living batteries for cursed energy, a direct consequence of Kenjaku’s ancient schemes that first entangled foreign governments in jujutsu affairs.

The central conflict of Jujutsu Kaisen Modulo is the struggle for coexistence. As the Simurians try to build a new home, tensions are inflamed by Maru’s twin brother, Cross, who seeks to provoke a war between the two species. The narrative weaves diplomatic intrigue with high-stakes battles, exploring themes of xenophobia and sacrifice. A major plot point involves the fate of Rika’s ring, a powerful heirloom left to Yuka by her grandfather. The ring is forcibly given to Tsurugi, leaving Yuka vulnerable when she is forced into a life-or-death duel against the powerful Simurian warrior Dabura to decide the future of their world.

In its final arc, the series reveals a dark future for the few surviving original characters. An aging Yuji Itadori, having witnessed centuries of loss due to his slowed aging, decides to follow a path similar to his greatest enemy. After the final elimination of all cursed spirits, Yuji chooses to become a cursed object upon his death, hoping to protect future generations long after he is gone, ensuring that humans and Simurians can finally live together in lasting harmony.