Jujutsu Kaisen's Culling Game has been ongoing for some time, bringing with it vicious death matches and self-discovery for the Jujutsu Sorcerers involved. Protagonists Itadori Yuji and Fushiguro Megumi, two first-year students at Jujutsu High, have been participating in the games – but they first came to the brutal event with a common goal: to free Gojo from the Prison Realm.
Itadori and Fushiguro hope to find the Angel, an imprisoned sorcerer who is using Hana Kurusu's body as a vessel. The students seek the cursed technique of the Angel, the only one known to be capable of deactivating the Prison Realm and thus freeing their beloved mentor, Gojo Satoru. However, foreshadowing in the Jujutsu Kaisen manga and anime suggests that Gojo may be able to free himself without the assistance of any other sorcerers.
How Did Gojo Become Imprisoned in the Prison Realm?
Since Chapter 90 of Jujutsu Kaisen, Gojo has been trapped inside an impenetrable realm, trapped by the ancient sorcerer Kenjaku, whose goal is to create a new age of Jujutsu parallel to the Heian Period. To accomplish this, Kenjaku made Binding Vows with a slew of cursed spirits and ancient sorcerers, then unleashed them in the Culling Games to create a "battle royale" and generate enough cursed energy for him to merge with Tengen.
However, Kenjaku had to protect himself from the one sorcerer who could stop him: Gojo Satoru. To do this, Kenjaku possessed the corpse of Gojo's best friend, Geto Suguru. The wise sorcerer chose to inhabit Geto due to his powerful Cursed Spirit Manipulation technique, but using the alias of Gojo's closest one certainly shocked the strongest sorcerer into a state of submission. While Gojo was confused, Kenjaku successfully trapped him in Shibuya, keeping him out of the way ever since.
Gojo Might Have to Sacrifice His Eye to Get Away
Aside from the Angel's cursed technique, there were two other ways for Gojo to be released from the Prison Realm: the cursed weapon The Inverted Spear of Heaven, which Gojo destroyed while fighting Toji Fushiguro, and Miguel's Black Rope, which Gojo also destroyed. However, according to one fan theory, Gojo will escape the Prison Realm by sacrificing one of his eyes – and thus his Six Eyes technique.
This theory stems from foreshadowing seen in the three Jujutsu Kaisen anime openings. In the first, Gojo is shown lifting his blindfold and revealing only his left eye. The second opening begins with a black cat (an animal commonly associated with bad luck) that looks back only with its left eye. In this same opening, Gojo is shown with his right eye covered by sunlight, once again revealing only his left.
Even in the mobile game, Phantom Parade, the opening has a sequence in which Gojo slowly looks up. When he looks back at the audience, glass shatters -- specifically over his left eye. Following this hefty foreshadowing, there are many scenes and panels in which Gojo is seen only revealing his left eye, adding more suspicion to this theory.
Gojo's Six Eyes Technique Might Be Important in His Escape
Gojo's distinctive Six Eyes technique allowed him to master and use Limitless with complete control. It is also the only thing that makes Gojo an enemy to Kenjaku. In the past, Kenjaku lost twice to sorcerers of the Six Eyes, failing to defeat them even after killing the previous user less than a month after their birth. The user was able to reincarnate into another body, rendering the ancient sorcerer's efforts useless.
The Prison Realm appears to be obsessed with eyes, and is designed as a cube with six faces, similar to a die block, with a different number of eyes on each face. It works by forming a Binding Vow with its user, and once a victim is found, the only way out without being opened from the outside is suicide. It's not a stretch to think Gojo could escape the realm by making his own vow and sacrificing one of his eyes.
Giving up an eye may be an ample sacrifice on par with the victim's death, as the Six Eyes technique is the source of much of Gojo's power. This would be an immense sacrifice to make and would make him abundantly less overpowered, so in theory it could be enough of a loss for the Prison Realm to release him.
Gege Akutami is renowned for his foreshadowing throughout Jujutsu Kaisen, so it's unlikely the imagery around Gojo's left eye is a coincidence. What this means is unknown, but if Gojo Satoru sacrifices an eye and loses his Six Eyes technique, he will most likely be unable to defeat Sukuna. The manner in which Gojo escapes the Prison Realm will undoubtedly be a watershed moment in the plot.