After a series of supernatural events involving a cursed object known as the "Sukuna's Finger," Yuji's life takes a dramatic turn. When his friends inadvertently unleash a curse that threatens their lives, Yuji swallows the cursed object to protect them.

This act not only grants Yuji immense strength but also makes him a host for Ryomen Sukuna, a powerful and malevolent demon. He is soon discovered by Satoru Gojo, a charismatic and skilled Jujutsu Sorcerer who introduces Yuji to the world of curses, sorcery, and the Jujutsu High School. As Yuji joins forces with Gojo and other sorcerers-in-training like Megumi Fushiguro, he learns about the existence of curses and the duty of sorcerers to protect humanity by exorcising these malevolent beings.