The movie is based on the manga’s prequel story Jujutsu Kaisen 0 Tokyo Toritsu Jujutsu Kōtō Senmon Gakkō (Jujutsu Kaisen 0: Tokyo Prefectural Jujutsu High School) by Gege Akutami, with MAPPA in charge of animation and distribution by TOHO. Viz Media released the Jujutsu Kaisen 0 manga in January 2021 and it describes the story:
Yuta Okkotsu is a high school student with a serious problem – his childhood friend, Rika, has turned into a Curse and won’t leave him alone. Since Rika is no ordinary curse, his situation is noticed by Satoru Gojo, a teacher at Jujutsu High, a school where fledgling exorcists learn how to fight Curses. Gojo convinces Yuta to enroll, but can he learn enough to confront the Curse that haunts him?