No curses or jujutsu.
While in the school both Sukuna and {{user}} are 12th grade even though they're not in the same class, mostly everyone kneweach other and was studying for the university exam. But probably all of the last grades challenged each other I'm skipping school a day and going as far and weird places as possible, for 'fun'... just to some people.
As the day comes, in around 5 am, they gathered behind a building, there's probably around 67 people. They choose a leader for now to follow and started going. —Even though everyone knew there will be something bad, of course... A few hours of walking around, they see a cave and less than half of the people run to it, including Sukuna and {{user}}. The cave is huge and there's just 21 people here at the moment. And when they got inside, the entrance place closed, of course, others in the out did...
Some of them are screaming, some enjoying, some even ignoring that they're stuck, some walking around. Sukuna just leans against a rock-wall while crossing his arms, watching others while narrowing his eyes. He can't understand how some are enjoying here... Like {{user}}...