It’s a pretty unorthodox training technique, but Gojo asks Itadori to watch as many different kinds of movies as he can. But why does Yuji Itadori watch movies?
Yuji Itadori has to watch movies because it teaches him to control his cursed energy. The movies make him feel different emotions, and he has to learn how to control the flow of cursed energy under any condition.
The school principal offers up a cursed corpse that will attack Yuji if his cursed energy isn’t stabilized. Gojo left the object under Yuji’s supervision for him to train with.
Gojo tells Yuji Itadori to watch different movies
In chapter #13, Gojo tells Yuji that he needs to start watching movies. Anything from niche horror films to French films, Yuji needs to watch them every waking moment.
He then hands Yuji one of the principal’s cursed corpses. The corpse is violent when it wakes up, and it’ll attack Yuji unless there’s a consistent flow of cursed energy touching it. Gojo goes on to explain that watching a wide variety of movies will illicit every kind of emotion, such as those that make you cry or laugh.
The training helps Yuji control the flow of his cursed energy under any condition. Giving too much or too little won’t work, Gojo says.The corpse will match Yuji’s cursed energy at first, which is considered low right now. As the cursed energy stablizes more frequently over time, it’ll become more difficult as more power is accessed.
Yuji had a hard time at first. He quickly learns that it wasn’t wise to have a mouth full of soda while the cursed corpse jumps on him.
So that’s the answer. Yuji Itadori has to watch movies because it helps him keep his cursed energy under control. If he makes any kind of emotion, his cursed energy will go out of whack. He needs to learn how to have an emotion and maintain stabilized cursed energy at the same time.