Fujin hated being a baby.
There was no other way to put it. He hated every second of it.
His body was useless. His limbs flopped around like dead fish. He couldn't hold his head up. He couldn't grab anything. He couldn't speak. All he could do was lie there, stare at blurry shapes, and wait.
And wait.
And wait.
The first week, he tried to move. Tried to crawl. Tried to do anything. His arms wouldn't cooperate. His legs wouldn't listen. He was trapped inside a body that didn't work.
By the second week, he had given up.
He slept. He cried when the hunger got too bad. He ate. He slept again.
That was his life now.
"Should have wished to be five," he thought for the hundredth time. "Just five years old. That's all I needed. Walk. Talk. Do something."
But no. He had to be dramatic. He had to do it from birth. Now he was paying for it.
Days blurred together. His mother held him sometimes. His father looked in occasionally. Mostly he was left alone in a small room with nothing to do but stare at the ceiling and listen to his own thoughts.
The only thing that kept him sane was Shukaku.
---
The tanuki had woken up about three hours after the birth.
Fujin had been lying there, exhausted from crying, when a voice exploded inside his head.
"WHAT IS THIS? WHERE AM I?"
Fujin almost screamed. Instead he let out a startled baby noise that made his mother lean over and check on him.
"WHERE IS MY DESERT? WHY DOES MY CHAKRA FEEL WEIRD? WHO ARE YOU?"
Fujin couldn't answer. He was a baby. He couldn't say anything.
"ANSWER ME!"
The voice was loud. Annoying. Exactly how he remembered from the anime.
Fujin closed his eyes and focused. He had read about this. Jinchuriki could enter their inner world. It took concentration, but it was possible.
He concentrated.
The world shifted.
---
He was standing in a vast, empty space. Water stretched out in every direction, shallow and still. Above him, a dark sky with no stars. And in the center of it all, a massive cage made of black iron.
Behind the bars, two enormous yellow eyes stared at him.
Shukaku.
The tanuki was huge. His body was made of sand and fur, covered in purple markings. His tail flicked behind him like a whip.
"You," Shukaku growled. "You're the brat."
Fujin looked down at himself.
He was tall. Strong. His old body. The one from before. His hands were his own. His face was his own.
He smiled.
"Yeah. I'm the brat."
Shukaku slammed against the cage. The bars rattled but didn't break.
"Where is Gaara? What did you do with him?"
"Gaara is fine. He's not here. This is a different world."
"Different world? What nonsense is that?"
Fujin walked closer to the cage. Not too close. Just close enough to see the madness in those yellow eyes.
"This isn't the ninja world. No Hidden Villages. No Kage. No Akatsuki. You're in a new place now. With me."
Shukaku snarled.
"I don't believe you. Let me out of here and I'll crush you into sand."
"I'm not letting you out. And even if I did, you wouldn't crush anything."
Shukaku's tail lashed against the cage.
"You think you can hold me? I am Shukaku! The One-Tail! I have slaughtered armies!"
Fujin raised his hand.
Wood sprouted from the ground beneath his feet. Thick roots. Heavy branches. They coiled around the cage, wrapping it in layer after layer of living wood.
Shukaku's eyes widened.
"Mokuton? How do you have Mokuton?"
The wood tightened. The cage groaned. Shukaku backed up a step.
Fujin lowered his hand.
"I have a lot of things. Now. Are you going to listen? Or do I need to squeeze a little more?"
Shukaku stared at him for a long moment.
Then he laughed. A rough, barking sound.
"Fine. Fine. You've got guts, kid. I'll give you that."
He settled down, curling his tail around himself. His eyes were still sharp, but the aggression had faded.
"Now. Explain. Where am I? What is this place?"
---
Fujin sat down cross-legged on the water. It held him like solid ground.
"This world is called Jujutsu Kaisen. Ever heard of it?"
"No."
"Didn't think so. It's not your world. No chakra here. Instead, people use cursed energy."
"Cursed energy?"
"Negative emotions. Fear, anger, hatred. It turns into power. And that power creates monsters called cursed spirits."
Shukaku's ears perked up.
"Monsters?"
"Yeah. Big ones. Small ones. They eat people. Sorcerers hunt them."
"And me? Why am I here?"
Fujin leaned back on his hands.
"I asked for you. When I made my wish, I asked for you to be sealed inside me."
Shukaku's eyes narrowed.
"You wished for me? Why?"
Fujin thought about it.
"Because you're strong. Because I need a partner. Because I didn't want to be alone."
Shukaku was quiet for a moment.
Then he snorted.
"You're strange. Most people who get me sealed inside them are terrified. They spend their whole lives trying to get rid of me."
"I'm not most people."
"No," Shukaku said slowly. "You're not."
He studied Fujin with those yellow eyes.
"You have the Mokuton. That's Hashirama's power. And I can feel something else in you. Something old. Something sharp."
"Uchiha. Uzumaki. Senju. All three."
Shukaku's tail stopped moving.
"All three?"
"Yes."
The tanuki let out a low whistle.
"You really aren't playing around, are you?"
"I don't have time to play. My brother is going to be born in five years. And when he grows up, he's going to be a problem."
"Your brother?"
"Sukuna. You don't know him yet. But you will."
Shukaku scratched his ear with a claw.
"And you want to fight him?"
Fujin shook his head.
"I want to know him. Understand him. See if he can be something other than what he becomes."
"And if he can't?"
Fujin was quiet for a long moment.
"Then I deal with it."
Shukaku laughed again.
"I like you, kid. You're honest. Stupid, but honest."
He stretched out, his sand shifting around him.
"Fine. I'll stay. For now. But don't think you can boss me around. I'm not your pet."
"Wouldn't dream of it."
Shukaku smirked.
"Good. Now get out of here. You've got training to do, and I want to sleep."
Fujin stood up.
"One more thing. In here, I'm not a baby. I can move. I can fight. I can train."
Shukaku raised an eyebrow.
"So?"
"So I'm going to be spending a lot of time here. Practicing. Getting stronger."
The tanuki grunted.
"Your mind, your space. Do what you want. Just don't wake me up unless it's important."
He curled up and closed his eyes.
Fujin smiled.
Then he let the mindscape fade.
---
The next few months were a routine.
Real world: sleep, eat, cry, wait.
Mindscape: train.
The system shop was open. Fujin had points. One hundred thousand of them.
He started with the basics.
[Uzumaki Specials Pack – Purchased]
[Adamantine Sealing Chains – Mastery Acquired]
[Healing Bite – Mastery Acquired]
[Mind's Eye of Kagura – Mastery Acquired]
[Uzumaki Sealing Arts – Mastery Acquired]
The knowledge flowed into him. Every seal. Every chain. Every sensory technique. It was like he had been born with it.
[Senju Specials Pack – Purchased]
[Wood Release – Already Owned]
[Regeneration – Passive Unlocked]
[Vitality Boost – Passive Unlocked]
[Chakra Pool Expansion – Passive Unlocked]
His body in the mindscape pulsed with new energy. He could feel his reserves growing. His healing speeding up. His life force strengthening.
[Uchiha Specials Pack – Purchased]
[Fire Release Affinity – Unlocked]
[Perception Boost – Passive Unlocked]
[Chakra Control Refinement – Passive Unlocked]
The fire came easy. He could feel it in his chest. The perception was sharper now. Everything in the mindscape was clearer, slower.
He spent hours practicing.
The Uzumaki chains came out of his back. Golden and solid. He wrapped them around imaginary targets, practiced restraining, sealing, binding.
He worked on the Mind's Eye, pushing his awareness outward. In the mindscape, there wasn't much to sense. But he practiced anyway.
He formed wood with his hands. Trees. Walls. Weapons. Each time, it got easier.
Shukaku watched him sometimes. Just watching, not talking.
After a few weeks, the tanuki finally spoke.
"You're going to burn yourself out."
Fujin didn't stop moving.
"I can't afford to burn out."
"You're a baby. You have time."
"I have five years. Then Sukuna is born. Then I have to be ready."
Shukaku snorted.
"Five years is a long time."
"Not long enough."
He kept training.
---
Weeks turned into months.
Fujin learned to walk in the real world at six months. Not well. Not fast. But he could do it.
His mother found him standing by the window one morning, staring at the moon.
She screamed.
His father laughed.
"That's my boy."
Fujin didn't say anything. He didn't talk. Talking would bring questions. Questions would bring attention. Attention was dangerous.
He stayed quiet. Stayed small. Stayed invisible.
But in the mindscape, he was growing.
His chains were stronger now. His seals were tighter. His wood could create entire forests in seconds.
Shukaku started talking more.
"You know," the tanuki said one day, "you're not like the others."
"What others?"
"The ones who had me before. Gaara's father. The other jinchuriki. They all treated me like a weapon. Something to use and control."
Fujin was practicing a sealing formation on the water. His hands moved through the signs smoothly.
"How should I treat you?"
Shukaku scratched his chin.
"I don't know. Like a partner, I guess. Someone who's stuck with you whether you like it or not."
Fujin looked up.
"Do you want to be here?"
Shukaku was quiet for a moment.
"No. But I'm here. Might as well make the best of it."
Fujin nodded.
"Then partners it is."
Shukaku's tail flicked.
"Don't get soft on me, kid."
"I won't."
But he smiled, and Shukaku saw it, and for once the tanuki didn't say anything.
---
Months passed. Then a year.
Fujin was one year old now. He could walk properly. He could say a few words. Enough to seem normal.
His father trained him sometimes. Basic stuff. Stances. Breathing. How to feel cursed energy.
"You have a lot of it," his father said one evening.
Fujin said nothing.
"More than me."
Still nothing.
"Don't tell anyone."
Fujin nodded.
His father looked at him for a long moment.
"Strange child."
Then he walked away.
That night, Fujin went back to the mindscape.
Shukaku was waiting.
"Your old man knows something's off."
"Let him wonder."
"He'll figure it out eventually."
"Maybe. By then, it won't matter."
Shukaku laughed.
"You're cold, kid. I like it."
Fujin sat down on the water and opened his status.
---
[Status: Ryomen Fujin]
[Age: 1]
[Level: 5]
[XP: 350/500]
[SP: 92,000]
[Titles: Newborn Jinchuriki, Hidden Prodigy]
[Bloodlines: Uzumaki (Pure), Uchiha (Pure), Senju (Pure)]
[Jinchuriki: Shukaku (One-Tail) – Stable]
---
[HP: 12,500/12,500]
[CP/CE: 18,300/18,300]
[Regeneration: Active – Advanced]
---
[Skills & Mastery]
Cursed Energy Control: B
Uzumaki Sealing Chains: A
Uzumaki Sealing Arts: A
Mind's Eye of Kagura: B
Wood Release: B
Fire Release: C
Hand Seals: B
---
[Passive Traits]
Uzumaki: Massive Vitality, Enhanced Lifespan, Sensory Prowess, Sealing Affinity
Senju: Rapid Regeneration, Colossal Energy Reserves, Life Force Amplification
Uchiha: Keen Perception, Fire Affinity, Refined Control