Jujutsu Kaisen: What Is The Prison Realm? How Can It Seal Gojo

Prison Realm, also known as Gokumonkyo, is a special-grade cursed object.

JUJUTSU KAISEN © 2018 by Gege Akutami/SHUEISHA Inc.

After seeing Kenjaku seal the strongest sorcerer, Gojo Satoru, many of you must have been perplexed, and soon many more will be as the episode where Gojo is sealed gets aired.

To satisfy your curiosity and solve your confusion, in this article, we will tell you all about the taboo object, the Prison Realm.

So without wasting any time, let’s get into it.

What Is Prison Realm?

Prison Realm, also known as Gokumonkyo, is a special-grade cursed object containing a barrier that can seal absolutely anything and anyone in a pocket dimension. I repeat, anything and anyone.

Also referred to as a taboo object, the Prison Realm is a living barrier so powerful that there is no one or nothing it cannot seal.

It is the final remains of the Buddhist monk Genshin, and in its unused form, it resembles a cube small enough to fit in one’s hand. In real life, its size might be close to a Rubix’s cube.


The cursed object is wrapped in talisman contrains. Once sealed, it cannot be opened again, and thus only one occupant can exist in the Prison Realm at a time.

Nothing can break the prison realm. Only the user of the Prison Realm can open it again, or the one trapped inside must kill themselves.

Now that we understand what a Prison Realm is, let’s see how to seal something with it and how to unseal it.

Yes, you heard me right, it can be unsealed. First, let’s understand how it works.

How Does Prison Realm Work?

To seal anything, one needs to place the object in front of the target and chant “Gate Open”. Then the Prison Realm opens, and after one minute, the target is captured.

After the user chants “Gate Close,” the object closes back to its previous form, and the victim is now sealed for eternity.

When the Prison Realm opens, the four corners of the cube expand, showing its mass of stretched flesh.

The mass has a giant bleeding eye in the middle, which is kept open with stitches. This keeps the eye open to stare at its victim.

Once the realm has laid its eye on its target, the giant eye stares at the victim for a whole minute inside the victim’s mind.

When Kenjaku opened the Prison Realm in front of Gojo Satoru, the sorcerer’s gaze was met by the giant bleeding eye.


Gojo attempted to flee, but at that moment, Kenjaku revealed himself in Geto’s body. This distracted Gojo for an instant, as he had already killed his friend Suguru Geto a year ago.

Although Gojo got distracted only for an instant in real time, it was worth a minute in his mind, thus fulfilling the condition of the Prison Realm.

Then the mass of flesh transferred to his body in a flash, ensnaring him. Once the flesh captures the victim, it immobilizes them.

The flesh also blocks any access to the victim’s cursed energy, and thus, Gojo was not able to do anything.

The sealing was completed when Kenjaku chanted “Gate Close,” reverting the object back to its small cubic form.

While the Prison Realm processes a strong sorcerer like Gojo after sealing, it becomes extremely heavy and cannot be moved.

Several eyes also opened on the surface of the cube. Inside the pocket dimension, time does not flow, and the victim is surrounded by dark skeletons with an ominous atmosphere.

Now, as I mentioned earlier, there is a way to unseal the prison realm. So let’s learn how.

How To Unseal The Prison Realm?

The Prism Realm actually exists as two halves. The primary first half is called the Front gate, and it is what is used to seal anything inside.

While the other half is called Back Gate and was in the possession of Master Tengen.

In Chapter 145, Master Tengen explained that, knowing how powerful the Prison Realm is, she sealed the Back Gate of the Prison Realm.


She did this in hopes of hiding its existence. Unfortunately, Kenjaku found the Front gate somewhere overseas and used it to seal Gojo.

Once sealed, the bearer of the Front gate has the authority to open it and unseal the Prison realm. The bearer of the back gate cannot open it.

The only way to unseal it is to break it open, but as mentioned at the start, nothing can break it.

In the same chapter, Master Tengen explains that to break the back of the Prison Realm, one would require one of the two special cursed tools.

These are the Inverted Spear of Heaven, which nullify the cursed technique. And the Black Ropes, which disrupt and cancel the cursed technique’s effects.

Unfortunately, Gojo himself destroyed both of these options 11 years ago. He either sealed it or destroyed it after his fight with Toji Fushiguro.

During the Night Parade of the Hundred Demons, Gojo got rid of all the Black Rope. Yuta had even gone overseas to look for it, but to no avail.

The only way left to unseal Gojo was through the culling game player named Hana Kurusu. Hana is possessed by a reincarnated sorcerer from a thousand years ago called Angel.

Angel’s cursed technique can extinguish any cursed technique and could thus break the back of the Prison Realm.

In chapter 221, using Angel’s power, she casts Jacob’s Ladder, and Gojo finally gets unsealed.