Itadori was the perfect vessel to house the king of curses, Ryomen Sukuna; a special case among special cases, someone who demonstrated the skill and ability to control Sukuna despite eating a special grade cursed object.
To be honest, he was most probably engineered to be that way. Despite that, there appears to be a slight blemish in his record. Or should I say, blemishes?
The incidents in question happened first, at the Eishu Juvenile Detention Center, where Itadori was unable to switch back, eventually leading to his first ‘death’. And then the second instance happened at Shibuya, where Sukuna went on to kill a lot of innocent people!
What exactly happened in these two scenarios? Why wasn’t Itadori able to switch back? Was it because he was completely drained fighting?
In the juvenile detention center, he was fighting the cursed spirit. And at Shibuya, he was all spent fighting Choso.
Well, no! The answer to one of this phenomenon rests on a fundamental principle of the Jujutsu world. Let’s sum it up and call it the law of equivalent exchange for better understanding.
And the second instance? Well, Itadori had no control over it whatsoever!
Read on to know more!
Why couldn’t Itadori switch back at the Juvenile center?
To answer in short, Itadori couldn’t switch back with Sukuna at the Juvenile center because it was a side-effect of trying to use him without restrictions. Every action you take has a reaction of some sort in Jujutsu world!

Confusing? Allow me to elaborate.
In the juvenile center, Itadori forced Sukuna to come out and made him fight. Our protagonist was having a hard time against the special grade cursed spirit on his own. He was almost at death’s door. But despite his difficulties, Sukuna was in no mood to emerge or to help him out.
The king of curses had no intention of dancing to Itadori’s tunes. He even threatened to kill Megumi and Nobara if he were to be summoned.
The threats worked, that is, until Itadori decided to give up control of his body and make Sukuna appear and fight much to his chagrin.
As I mentioned before, there is hardly any stuff in the Jujutsu world that comes for free. A balance needs to be maintained and such exchanges almost always have to be mutual. This is where binding vows and other contracts come into picture. The law of equivalent exchange is always at play in the JJK verse.
Itadori could have borrowed Sukuna’s power IF the latter agreed to it. But there was no mutual understanding, and strictly speaking, no contract between them.
So, in return for forcefully summoning Sukuna to help him, Itadori was forced to lose control of his body for an extended period of time. Meaning, he couldn’t switch back when he wanted.
Once again, he didn’t lose control of his body completely, but only for an extended period of time than usual.
As Sukuna himself would later point out in chapter 11, Itadori was being too greedy. He used Sukuna as a power-up and ended up facing the consequences of his actions.
Some argue that Itadori had let Sukuna out before to fight (remember one finger Sukuna vs Gojo?), and he was able to take control of his body easily then. However, they forget that the situation at the detention center was very different from the time when Itadori ate the first finger.
Back then, Sukuna himself wanted to come out and fight. It was not simply because Itadori forced him to. And so, the latter was able to switch with Sukuna in 10 seconds as commanded by Gojo. This is confirmed in chapter 11.

When Sukuna realized Itadori couldn’t switch back, he also realized that this situation wouldn’t last for long. And that’s the reason why he decided to hold Itadori hostage by pulling out the heart from his body.
Just to clarify, Sukuna does not let Itadori switch after the fight with Megumi too, instead Itadori takes control of his body out of his own will despite knowing that he would die. That’s just the kind of guy Itadori is!
Now, let’s move on to the next part.
Why couldn’t switch back with Sukuna at Shibuya?
To answer in short, Itadori couldn’t switch back with Sukuna at Shibuya because he was force fed 10 fingers at one go.
This case was entirely different from what happened at the Juvenile Detention Center.
After Junpei’s death, Itadori had vowed that he would not rely on Sukuna’s powers to win any fight for him. Since, he was in perfect control of his body, there was no risk of Sukuna even coming out without him wanting that to happen.
However, this only worked if Itadori kept on eating one finger at a time. If Itadori had consumed Sukuna’s fingers one by one, then even after consuming all 20 fingers, Itadori still would have been in control.
The worst part was that Geto/brain/Kenjaku (call him what you may) was aware of this tiny detail, and he was ready to exploit it for his own benefit.

Itadori losing control of Sukuna was something that Kenjaku wanted to happen at Shibuya. The ensuing chaos that the King of curses would cause would help him achieve his goals, i.e. to flee with the Prison Realm with Gojo trapped in it.
And so, he entrusted Jogo to feed Itadori the 10 fingers that they had stolen from Jujutsu High during the Kyoto Sister School Event.
Yes, it was not a random attack. Kyoto Sister School attack was carried out as a precursor to prepare for Shibuya. If you didn’t notice, they also tested out their barriers over there. Read the following blog to know more!
Read More: Barriers in Shibuya Explained (and how it tied in to Kyoto Sister School event)
I could keep ranting about how everything in the JJK manga is brilliantly connected and concocted, but let’s leave it at that.
Coming back to Jogo, he listened to Kenjaku’s instructions and fed Itadori 10 fingers at once. I don’t know if Itadori being beat up played any part in it, however, after consuming 10 of Sukuna’s fingers at once, Itadori lost control of his body momentarily.
He was only able to regain control after Sukuna defeated Mahoraga.
Sukuna switching with Itadori and going crazy ensured that everybody’s attention shifted from Kenjaku to Sukuna for a brief moment. And Sukuna did cause enough chaos in Shibuya for Itadori to feel guilt for a complete lifetime.

What do you think of Itadori not being able to switch back at both these instances? If you still have any nagging doubts regarding this, feel free to hit me up in the comments below, or ping me on Tumblr/Reddit!