After entering the room, Shisui took out a scroll.
It was the key that released the seal on Naruto, made by Minato Namikaze, and kept at Mount Myōboku after his death.
As for why it ended up in Shisui's hands, it was naturally given to him by Ren.
When Ren first Jiraiya Yuuki after Yuuki became Hokage, Ren asked him to leave the key in Konoha.
Sealed space.
Naruto and Shisui stood in front of a huge door, behind which, of course, stood the Nine-Tails had been waiting for a long time.
This kind of operation could actually be done by both Naruto and Shisui in Konoha at any time.
The reason we had to come to Turtle Island was precisely because of the effect this dazzling space had.
Ren doesn't know the specific reason; everything depends on Orochimaru's progress.
The strange room on Turtle Island has only one effect: the Tailed Beast Chakra that can be stolen here can be truly stolen.
If Naruto and Shisui can seize half of Nine-Tails 'Chakra and suppress Nine-Tails, then they will no longer need Nine-Tails's permission to use that Chakra in the future.
If this operation were carried out in Konoha, the stolen Chakra would be a one-time event.
Historically, it's not uncommon for people to have done this before; both Mito Uzumaki and Kushina Uzumaki used the Nine-Tails Chakra in this way.
When the Nine-Tails' power is needed, we'll plunder it from the sealed space. We'll use as much as we can, and any leftovers can't be stored. We'll just plunder again next time we need it.
Not only in Konoha, but the other Jinchūriki are in similar situations, the only difference being that some have a better relationship with the Tailed Beast.
For example, Yagura, the former Jinchūriki of the Three-Tails, didn't need to steal it; he could just ask Isobu, for it.
Even if Isobu gave it to Yagura voluntarily, and he had no ill intentions towards Yagura, Yagura still had to suppress the corrosive nature of the Yagura Tailed Beast Chakra itself.
The characteristics of Turtle Island can be summarized in two simple points.
Firstly, once you seize it, you can keep it permanently until you die. While other methods might yield wages, here you get shares.
Secondly, it eliminates the corrosive properties of Tailed Beast Chakra, making it clean and hygienic, so it can be used by oneself or others.
Shisui and Naruto, whose consciousnesses had entered the sealed space, did not notice that shortly after they entered, the already colorful and dazzling training space suddenly shone brightly, turning into a sea of light before slowly dimming and returning to its original state.
"Nine-Tails, I'm releasing you now. Will you give me your Chakra from now on?"
Naruto, having frequently visited the sealed space over the years, knew that the next step required defeating the Nine-Tails and stealing its Chakra.
Naruto, who possesses extraordinary empathy, felt that this would definitely make Nine-Tails unhappy, so he decided to try to use their relationship to get Nine-Tails to cooperate willingly.
After Naruto finished speaking, the room fell silent.
Nine-Tails stared intently at Naruto, not because he was persuaded by Naruto's talk-no-jutsu, but Nine-Tails noticed that Naruto seemed to have undergone some kind of change.
As the two stared at each other, Naruto assumed Nine-Tails was seriously considering his proposal, and the anticipation and joy in his eyes became increasingly apparent.
Looking at Naruto's naive and somewhat silly appearance, Nine-Tails) categorized his earlier feeling as an illusion.
Could this silly boy possibly change, or become even sillier?
"Kid, aren't you dreaming? You think you can boss me around? Letting you use some of my Chakra is a reward for your good manners!"
After realizing that it was just a momentary lapse of judgment on his part, Nine-Tails looked down at Naruto and said...
"That tiny bit of Chakra was just something I accidentally let slip, like the waste you humans excrete. I'm giving you that waste as a reward, not a license for you to take advantage of me, understand?"
This wasn't the first time Nine-Tails had said these words, but before, only Naruto had heard them. Now, with his idol right beside him, Nine-Tails's words made Naruto feel like he was going to die.
Naruto initially felt sorry for the Nine-Tails being imprisoned there, but now that he was leading others to steal its things, he felt somewhat guilty.
After Nine-Tails said those words in front of Shisui, it felt no remorse whatsoever.
At the age of ten-something, it's the beginning of a rebellious phase, and also a time when people are quite concerned about saving face.
Since Nine-Tails said that to him, Naruto plans to pluck Nine-Tails's fur off completely and then ignore it for a month. Well, a month is too long, a week!
Naruto turned his head away from Nine-Tails and spoke to Shisui.
"Brother Shisui, let's begin, I'm ready!"
Shisui nodded and handed the key to Naruto then lifted his shirt, pressed the key against the seal on his stomach, and twisted it hard.
As Naruto moved, the seals symbolizing the seal on the giant gate between the two gradually peeled off and disappeared.
"Clang!"
Without any hesitation, Nine-Tails pushed open the door and went out.
"Kid, the seal has broken. You don't actually think that Uchiha Clan ninja next to you can protect you, do you? Let me tell you, he's not qualified!"