Over the next ten or so days, Uchiha Sora came to Kushina's place every day without fail to study sealing techniques.
During this period of learning and exchange, the relationship between Kushina Uzumaki and Uchiha Sora deepened rapidly.
It couldn't be helped—they were both drawn to each other's looks.
During this time, Mikoto Uchiha also came by several times after learning that Sora was studying sealing techniques with Kushina.
All of this was observed by the Anbu and Root shinobi lurking in the shadows, but with orders from the Third Hokage and Danzo, none of them interfered.
…
[...Your Four Black Mist Formation has reached perfect mastery.]
[...Your Four Violet Flames Formation has reached perfect mastery.]
[...Your Four Red Yang Formation has reached perfect mastery.]
[...Your Sealing Barrier Technique has reached perfect mastery. You have further developed Sealing Barrier 2.0.]
…
"That's it! There's really nothing left! I've squeezed out every last bit of sealing knowledge I have!"
"What kind of monster are you? How can a human possibly learn this fast?"
"You've already surpassed me in sealing techniques—and now you can even teach me instead!"
Kushina sprawled across the table with a lifeless expression, puffing her cheeks as she glared at Uchiha Sora.
This was just too much.
She felt like Sora had been sent by Tsunade specifically to crush her confidence.
And what made it worse—fine, having strong learning ability was one thing—but he could even innovate and derive stronger sealing techniques at terrifying speed.
That was simply unreasonable.
"Hehe."
Seeing this, Uchiha Sora couldn't help but poke her puffed-up cheek and said with a smile,
"Come on, you're not bad at all. Aside from me, there's probably no one in the shinobi world who can surpass you in sealing techniques."
"By the way, I heard that the Uzumaki clan has a sealing technique called Adamantine Sealing Chains. Can you teach me that?"
He had his eye on that technique for quite some time.
After all, it could suppress Tailed Beasts—clearly no ordinary ability.
"Huh?"
Kushina stared at him speechlessly.
"Do you even know what you're saying?"
"If I could teach you, do you think I wouldn't?"
"Since you already know about that technique, then you should also know that it's exclusive to the Uzumaki clan. It requires Uzumaki bloodline to learn it."
It wasn't that she was being stingy.
After spending these days with Uchiha Sora, she was actually quite willing.
Their exchange wasn't one-sided.
During the learning process, Sora had even guided her in refining her existing sealing techniques, greatly improving her progress.
At the same time, he had also taught her all the new sealing techniques he had derived.
They were mutually benefiting and elevating each other.
She would have loved to pass on Adamantine Sealing Chains to him—just to see whether he could develop an even stronger version from it.
If that happened, she was certain an enhanced version would easily suppress the Nine-Tails, finally letting her achieve her dream of dominating it.
"Achoo!!"
Inside Kushina's newly reinforced Eight Trigrams Seal space, Kurama suddenly sneezed.
"Damn it… Kushina must be cooking up something again."
"Bang! Bang!"
It raised its claws and struck the sealing cage.
The cage didn't budge at all. Instead, the recoil made its claws ache, further fueling its frustration.
"That damned Uchiha Sora… why did he have to create such a powerful seal?"
"How am I supposed to escape now?"
It felt like escape was completely hopeless.
Fortunately, Sora had at least shown some conscience—he had persuaded Kushina to treat it better and expanded the sealing space significantly.
Now, although the cage was even more unbreakable, the space inside had expanded over a hundredfold.
The scenery had also changed.
There was sky, grasslands, mountains, and flowing rivers.
Even if it was all constructed from chakra, it was far more comfortable than before.
Kurama could even run freely within the sealed space.
Aside from not being able to leave… this isn't so bad…
The thought suddenly surfaced in its mind—
And in the next instant, its expression changed drastically.
"No! How can I think like that?!"
"I was meant to be free! These damned humans imprisoned me. How can I submit just because of a little kindness?"
"Absolutely not!"
A Tailed Beast never submits!
Yet the very next moment, it casually conjured a pile of potato chips and soda using chakra—
"Crunch! Crunch!"
"Glug! Glug!"
It ate and drank happily, as if the one who had just sworn eternal defiance wasn't it at all.
Kurama could only sigh inwardly.
What choice did it have?
With this new seal, unless Kushina died, its chances of escape were practically nonexistent.
And with a monster like Uchiha Sora outside, even escaping now might not be a good idea.
Better to stay put.
At least the snacks Kushina had brought in that one time were pretty good.
Though she had only brought them once—
But who was it?
The great Kurama!
After tasting them once, it memorized their flavor and appearance and simply recreated them with chakra.
The taste was identical.
…
Outside—
Hearing Kushina's words, Uchiha Sora smiled.
"Of course I know it requires Uzumaki blood. But I still want to try."
"Who knows? I might succeed."
Kushina blinked, then nodded in realization.
"That's true… If it's you, it might actually work."
"After all, you're ridiculously abnormal."
"Here. This is it. Give it a try."
She took out a scroll and handed it to him.
"Thanks."
Uchiha Sora accepted it, then continued,
"Also… can you give me a drop of your blood, and a bit of Nine-Tails chakra?"
"Huh?"
Kushina froze.
"Why? What do you suddenly need my blood and the Nine-Tails' chakra for?"
"You're not planning to do something shady, are you?"
She looked at him suspiciously, as if examining a scumbag.
Uchiha Sora: "…"
Thump!
He flicked her on the forehead.
"Hey! That hurts!"
Ignoring her protest, he explained,
"I want to study the nature of the Uzumaki bloodline. Maybe I can replicate the Uzumaki physique."
"At the very least, it should help me learn Adamantine Sealing Chains faster."
"As for the Nine-Tails' chakra, I'm interested in its composition. I want to see if I can figure out a way to fully control Tailed Beasts."
"So? Are you giving it or not?"
He had always been deeply interested in the Uzumaki physique—
Their powerful vitality,
Their massive chakra reserves,
And abilities like the Kagura Mind's Eye.
All of it was something he wanted.
He intended to develop corresponding cultivation methods.
If he could gain the Uzumaki physique and abilities through training alone, wouldn't that be perfect?
Of course, he wouldn't treat Kushina unfairly.
Afterward, he planned to give her refined training methods and a way to purify and enhance her bloodline.
And someday—
He would give her even more.
After all—
He had already decided.
She would be his.
Minato… sorry. You'll have to find someone else. You and Kushina haven't even started yet anyway.