Ruins of Tanzaku Castle. Immediately after the battle.
Tsunade knelt in the dust, her hands hovering over Naruto's chest. The green glow of medical chakra flooded the terrible wound left by the Kusanagi sword.
"Hold on..." she whispered, biting her lip until it bled. "Don't you dare die, hear me?"
Jiraiya and the arriving Shizune stood nearby, afraid to breathe. The wound was fatal. A punctured lung, severed arteries, damaged ribs. An ordinary shinobi would have died from shock and blood loss instantly.
But the Uzumaki wasn't ordinary.
Tsunade, being the world's best medic, saw what was hidden from others' eyes.
She saw the red Kyūbi chakra cauterizing vessels, stopping the blood. That was expected.
But she saw something else too.
White threads.
A strange, dense energy permeating the boy's bones and tissues worked even in unconsciousness. It held shattered ribs in place, preventing them from piercing the heart. It pulled the wound edges together with the force of invisible sutures.
His body... it wants to survive on its own, Tsunade realized with awe. This isn't just demon regeneration. It's his own life force. It's dense as stone.
"He'll pull through," she exhaled, feeling the heart rhythm under her palms stabilize. "He's too stubborn to die."
***
The Inn. Two days later.
Naruto opened his eyes.
The ceiling wasn't spinning. The pain in his chest was dull, distant, like a memory rather than reality.
He tried to sit up, but a hand gently but firmly pushed him back onto the pillows.
"Lie down, hero. You lost a liter of blood."
Tsunade sat next to the futon.
She looked different. The puffiness from constant drinking was gone; her eyes were clear and stern. She was wearing her usual gray kimono, not the gambling robe.
"Am I alive?" Naruto asked hoarsely.
"Barely," Tsunade snorted. "If not for your demon and your strange vitality, we'd be ordering a wreath for you right now."
She took a glass of water from the table and helped him drink.
"You won," she said quietly when he leaned back.
"The bet?"
"The bet. Life. And... my faith."
Tsunade took the crystal necklace off her neck. It caught the sun's rays, playing with reflections on the walls.
"Didn't I say this necklace is cursed? It brings death to those who dream of becoming Hokage. But you... you withstood a sword strike and remained standing. Maybe the curse is broken."
She leaned over and placed the necklace around his neck. The stone lay on his chest, cooling the skin where a fresh scar lay under bandages.
"Wear it. And don't dare die until you become an old man yourself."
Naruto touched the crystal.
"Thanks, Granny Tsunade."
"Don't call me that!" she raised a hand to strike but stopped.
Instead of hitting him, she leaned lower and kissed his forehead. Softly. Carefully. Like she used to kiss Nawaki.
"Thank you," she whispered. "For waking me up."
She pulled away and sat back on the chair. The atmosphere in the room changed imperceptibly. Warmth gave way to cold, professional interest.
"And now, Naruto, we need to talk seriously."
Tsunade's voice became quieter and firmer.
"While you were unconscious, I operated on you personally. I repaired your lung, stitched arteries, and fused ribs. I know human anatomy better than anyone in this world."
She looked him straight in the eye.
"Your body is not the body of an ordinary shinobi."
Naruto tensed instantly. The relaxation vanished. Muscles under the blanket hardened, ready to spring. The gaze of his blue eyes turned cold; steel flashed in them. The secret of Cultivation was his main trump card and main danger. If the wrong people found out...
Tsunade noticed the change. She saw in him not a child, but a bristling beast cornered.
"Calm down," she raised her palms in a placating gesture. "I'm not here to interrogate you or hand you over to T&I."
"What did you see?" the Uzumaki's voice was hollow and wary.
"A second system," she answered directly. "It doesn't look like the Chakra Pathway System, but it is physically present. Like... invisible meridians piercing every muscle and bone. They are denser than ordinary channels. They held your body from total destruction when the Kusanagi sword pierced you. Ordinary flesh would have turned into mince. Yours—worked like reinforced concrete."
She paused.
"I asked Jiraiya."
The blonde exhaled slightly but didn't look away.
"And what did he say?"
"He said: 'It's his path. Don't interfere if you don't want to break what he's building.' He said you found the forgotten knowledge of your ancestors."
Tsunade leaned closer.
"I won't ask where or how you learned this. I won't demand scrolls. Every strong shinobi has their aces up their sleeve. But as your future Kage, I must know one thing: this power... will it kill you?"
"No," Naruto answered firmly. "Quite the opposite."
Tsunade nodded, accepting the answer.
"Good. Then listen to the order of the Fifth Hokage. Your anomalous physiology is henceforth classified as an S-rank state secret. In the medical log, I recorded it as a 'side effect of Bijū influence.' No one except me, Jiraiya, and Shizune will know the truth."
"It concerns not just me," the blonde suddenly added quietly, looking at his hands.
Tsunade froze.
"What do you mean?"
"I'm not the only one. There are three others."
He raised his gaze to the Hokage.
"Hinata Hyuga. Ayame Teuchi. Anko Mitarashi. I passed on part of my power and basic knowledge to them. Their meridians aren't as dense as mine yet, and the 'second system' is only forming, but an experienced medic might notice oddities. Especially in Hinata, who trains the hardest."
Tsunade covered her eyes with her hand and sighed deeply, heavily.
"You... Do you even understand what you're doing? Spreading an unknown technique that changes physiology like a cold? What are you trying to achieve with this?"
"I decided to give my loved ones a chance to survive," the Uzumaki parried harshly. "If you had such an opportunity, wouldn't you have used it?"
The words hung in the air like a heavy weight. It was a low blow, but it hit with facts.
Tsunade clenched her teeth; muscles on her cheekbones twitched. She looked at the guy—alive, despite the hole in his chest.
"Fine," she finally hissed. "Damn you. I will pull their medical files from the general hospital archive and transfer them to my personal supervision. Any examination—only through me or Shizune."
"Thank you," Naruto relaxed, leaning back on the pillow. The tension left. "That's... important to me."
"I get it," she chuckled. "But note this, kid. If you drive yourself to a state where I have to stitch your 'reinforced organs' again, I'll personally add a couple of scars."
The door creaked.
Shizune peeked into the room with a tray of medicine. Seeing Naruto conscious, she almost dropped the tray.
"Naruto-kun!"
She ran into the room, put the medicine on the floor, and knelt beside him.
"Y-you're awake!" her voice trembled. "You scared us so much... Your chakra almost faded."
She began to inspect his bandages. Her hands were warm and gentle.
"How do you feel? Anything hurt? Are you dizzy?"
"I'm fine, Shizune-san," the blonde smiled. "Just hungry."
Shizune looked at him. In her gaze was not only a medic's relief. There was admiration. She had seen his body during the operation—perfect, strong, built like a predator. And she had heard about his spirit when he stood against Orochimaru.
"I'll bring food," she squeezed his hand a little longer than necessary, and her cheeks turned slightly pink. "Lots of food. You need to recover."
Tsunade watched this with a slight smirk.
Looks like this kid has talent for more than just fighting.
***
Konoha Gates. A week later.
The sun stood at its zenith.
Guards Izumo and Kotetsu were bored at their post, discussing the latest gossip.
"They say Jiraiya-sama should return soon?" Izumo asked.
"Yeah. I see someone on the road."
A strange procession approached the gates.
A huge Toad Sage.
A Chunin boy with a bandaged chest but proud posture.
A girl with a piglet.
And a woman. A blonde with a diamond on her forehead, whose gait radiated such authority that one wanted to stand at attention.
Kotetsu rubbed his eyes.
"That's... that's..."
" The Legendary Sucker!" Izumo exclaimed. "Princess Tsunade! They found her!"
The group stopped at the gates.
Jiraiya smiled broadly.
"We're home."
Tsunade looked at the village. At the Hokage Rock, where her grandfather's face was carved. And the face of her teacher, who lost his last health for this place.
She took a deep breath. The air of Konoha smelled like home.
A Council representative came out to them, holding a bundle.
"Tsunade-sama," he bowed low. "The Council awaits you. We are ready for the inauguration."
He handed her the hat with the kanji for "Fire."
Tsunade took the hat. She looked at Naruto.
"Well, brat? Ready to serve under an 'old hag'?"
The Uzumaki smirked, touching the necklace.
"Only if you don't gamble away the village at cards."
Tsunade laughed. She put on the Hokage hat. The shadow from the brim hid her eyes, but everyone saw her smile—predatory and confident.
"Let's go. I have a lot of work. Need to cure old man Hiruzen, knock some sense into the Council, and get this village back on its feet."
They entered Konoha.
Residents, recognizing the Legendary Sannin, stopped and bowed. The news spread faster than the wind: The Fifth Hokage is here.
Naruto walked slightly behind, next to Shizune and Jiraiya.
He looked at the Hokage Rock. Four faces. Soon there would be a fifth.
One day... mine will be there too.
He clenched his fist.
The Pseudo-Core in his stomach hummed with steady, powerful force. He returned different. Stronger. More mature. With a goal that now seemed closer than ever.
Their mission was complete.
But clouds were already gathering in the shadows of the world. The Akatsuki had begun to move. Orochimaru, licking his wounds, had not forgotten the grudges.
The shinobi world was preparing for future upheavals.