After Kushina helped Nagato with his eyes, she threw herself into training.
One might think she would want to spend as much time as possible with her clan, but that wasn't the case for her. Kushina spent most of her life alone, with only Kurama around for support. She wasn't exactly… great at socializing. She was brash, loud, and sometimes too quick to snap at people she didn't know well. Around her clan, who looked at her with reverence and expectations, Kushina couldn't bring herself to relax.
It was enough for her that her people were rescued and were settling happily here in their new home. That was the dream she had fought for, wasn't it? To give them safety, security, and a chance at peace? She didn't need to spend every waking moment around them just to reassure herself of it. Their laughter echoing through the settlement, the sight of children running freely without fear- those things were enough.
But even so… every time she heard them talking warmly together, trading stories and smiles, there was a strange heaviness in her chest. A distance.
That was why she turned back to what she knew best: training.
She devoted herself to studying the Adamantine Sealing Chains, one of the two great secret abilities of the Uzumaki clan.
Now that they weren't traveling anymore, Kushina could finally focus without distraction. Every day, she sat cross-legged on the wooden floor of the training hall or on the quiet cliff overlooking the valley where her people now lived. Her hands trembled from the effort of channeling her chakra, straining to feel for something that wasn't there.
The writings of her ancestors, the stolen scrolls she had recovered from enemy villages, even the notes taken by the other survivors- they all gave hints, but none of them truly explained how to awaken the ability. Most Uzumaki weren't even born with the gift.
Out of all the survivors, only two had managed to awaken something special. Aina, the somewhat timid girl she had rescued from Kusagakure, had awakened the Mind's Eye of Kagura- just as Kushina herself had. And Akinari, her fiancé, bore the Adamantine Chains.
Kushina had once cornered him, pressing him for answers. But all he'd given her was a shrug and a frustrated shake of his head.
"They came in a moment of anger," he admitted. "Someone I cared about was about to die, and I reached for them. The chains just… answered."
That explanation had annoyed her to no end. It was vague and unhelpful. Did he think she could just conjure up life-and-death stakes whenever she wanted?
Still, Kushina clung to the thought that her bloodline was among the purest. She had been chosen to be the Nine-Tails' Jinchūriki for that very reason- her body could withstand it, and her chakra was among the greatest in the world. If anyone among the survivors could awaken the sealing chains, it would be her.
It was only a matter of time.
And yet…
Every day that passed without progress scraped at her pride.
By the fifth day, Kushina found herself snarling at the scrolls in frustration. She slammed one closed and threw it aside, her breath ragged.
"Stupid chains. Stupid clan secrets. Stupid- ugh!"
Her voice echoed off the walls. No one else was there to hear her tantrum, thankfully.
She pressed her palms over her eyes and took a deep breath.
Maybe she was overthinking. Maybe what she needed wasn't another scroll. Maybe she needed a fight.
----
Inside the seal space, she appeared in a flicker of thought.
The vast chamber greeted her as always: dark stone floors, endless black sky, and at the center, the massive barred gate. Lounging on the floor just outside it was Kurama in his natural form, his giant head resting on his paws, eyes closed in perfect serenity.
The sight of him sprawled there- so calm, and so untouchable- sparked a mischievous thought.
Kushina narrowed her eyes.
She crept forward on silent feet, one step at a time, her chakra carefully suppressed. Like a shadow, or a hunter. She could already imagine the smug look vanishing from his face when she startled him awake.
Except, the moment she leaned close enough to see the twitch of his whiskers, two blazing crimson eyes snapped open.
"Ahhh!" Kushina squealed, stumbling backward.
Kurama's chest rumbled with laughter, low and rich. "Did you really think you could sneak up on me?" His massive tails stirred lazily. "Where do you think your sensory abilities come from?"
Her cheeks puffed out, pink dusting her face. "That didn't happen!" she protested hotly.
He gave an unimpressed grunt. "Mhm."
She crossed her arms, glaring at him. "…You're insufferable."
Kurama tilted his head. "So I've heard many times." His sharp grin widened. "What do you want, brat?"
Normally, she would've brushed off the nickname, but for some reason, it stung lately. She shook her head, pushing aside the irritation.
"Can we spar?" she asked.
"I'm sleeping."
"You've been sleeping for like a thousand years!" she snapped, exasperated. Then, softening, she clasped her hands together with a pleading look. "Come on. Please?"
Kurama snorted. "Hmph. Fine."
His massive body shimmered, shrinking down until the towering fox was gone. In his place stood the tall, orange-haired man in his human form, his eyes still glowing faintly like embers.
He folded his arms, studying her. "How's your training?"
Kushina bit her lip. "Not well. I can't figure out how to unlock it, even with the writings."
"Figures," he said. "Many natural abilities can only be tempered in fire."
She frowned. "So you're saying I need to be in danger?"
"I'm saying," Kurama replied, stepping forward, "that desperation sharpens the soul."
They squared off across the stone floor.
Kushina took a steadying breath, drawing her chakra into her limbs. Kurama didn't even move at first- he simply stood there, arms crossed, watching her with faint amusement.
"Don't hold back!" she warned.
The corner of his mouth twitched. "You couldn't handle me if I did."
She charged anyway, chakra flaring around her fists. Her first punch met his palm, and the shockwave of impact rippled through the chamber. He hadn't even braced, yet he held her in place effortlessly.
"Tch!" She pulled back, spinning for a kick. He caught that too, his other hand flashing up.
"Too weak."
"Shut up!"
She gritted her teeth, pouring chakra into her arms, striking again and again. Kurama parried every blow with infuriating ease. His crimson eyes glowed, sharp and unwavering, as though daring her to do better.
Her frustration mounted. She lunged, feinted, tried to slip behind him. He caught her wrist and twisted, forcing her to stumble.
"Come on," he growled, his voice low with challenge. "You want those chains? Prove you're worthy of them."
Kushina panted, sweat beading at her temple. Her chakra roared, surging wildly. But no matter how she struck, Kurama was always one step ahead. Always just out of reach.
Her anger burned hotter.
"I'm not weak!" she shouted.
Kurama shoved her back with one arm, his expression sharp. "Then stop acting like it."
Something inside her snapped.
The rush of chakra tore through her body, wilder than before, laced with something ancient. She felt it stirring in her blood- thick and heavy, like molten iron. It hurt, searing from her stomach outward, as if chains were being dragged from her very core.
Her knees buckled.
And then-
In a yellow flash, golden chains burst from her back, shining with chakra. They whipped through the air, rattling like living things.
Kushina gasped, her wide eyes staring at them in awe. The links shimmered, radiant and unyielding, stretching out in all directions.
Kurama's eyes narrowed. His smirk faded into something quieter and more thoughtful. A flicker of dislike passed through his eyes, but it didn't last long.
One chain shot forward instinctively, wrapping around his arm before Kushina even realized what she'd done.
Her breath hitched. "I… I-"
Kurama tugged against the chain, testing its strength. It held firm. A low chuckle rumbled in his chest.
"Not bad, brat. Not bad at all."
Kushina sank to her knees, panting heavily. The chains slowly retracted, fading back into her body as exhaustion overtook her. But despite her fatigue, she couldn't stop the grin spreading across her face.
She had finally awakened the Adamantine Sealing Chains. The pride of her bloodline. With this, her vitality, and the Mind's Eye of Kagura, Kushina felt as though her clan's legacy had been reborn in her veins. Every fragment of the Uzumaki- once scattered, broken, and hunted- lived on fully in her.
But she knew this was only the beginning. She was not only an Uzumaki- she was the Nine-Tails' Jinchūriki. A vessel, a partner, and now, a wielder of powers that made her stand above the world's strongest shinobi.
Though she had poured herself into the art of fūinjutsu these past months, her training had not stopped there. The chains were not meant to exist in isolation. Neither was she.
Her progress in Tailed Beast Mode was proof of that. Where once she had only been able to manifest six tails, the same form that had laid waste to Konoha, now she could call forth eight.
At a glance, it might seem a small difference. But Kushina knew the truth. Each tail was not additive; it was an exponential leap. Each tail gave more strength, speed, and endurance than the last.
The ninth tail remained distant. The most difficult threshold to cross, the one that demanded perfect synchronization with Kurama's chakra- perfect alignment of will and spirit. Yet Kushina was certain of one thing: if she reached that final stage, not even all the Kage together could stand against her. The shinobi world would tremble.
That was a dream for the future. For now, her path was clear: she needed to fuse the old with the new. To weave her Adamantine Sealing Chains into her Tailed Beast Form, binding destructive chakra with unbreakable restraint. She already had a few ideas.
And beyond that, she had not forgotten her other inheritance. The Mind's Eye of Kagura. Already, it allowed her to sense chakra across vast distances with terrifying clarity. Combined with Kurama's malice-sensing ability, she had the potential to develop a perception so sharp it would border on omniscience.
But developing new techniques is not simple. She was walking on ground no one had ever walked on before. Creating something new was always the hardest.
Kushina clenched her fist, feeling the weight of the chains pulse in her blood, along with their promise. She was Uzumaki Kushina- her clan's greatest protector and leader. She'd do whatever it took to make her, Kurama, and the Uzumaki survive in this world.