The standard practice in this situation is to take out Sukuna, which isn't good news for Yuji — many want him dead. However, powerful Sorcerer Satoru Gojo is impressed by the way Yuji is able to maintain control of his body and decides to bring him to Tokyo Prefectural Jujutsu High Scho...
In terms of where the story of JuJutsu Kaisen is in the anime, we don’t know too much about the back story of Sukuna. The most information that we’re given about him comes from the interrogation that good old Gojo conducts on Itadori after they subdue him post eating the finger. Gojo...