"An actual gate that pierces worlds…"
Naruto's consciousness snapped back to his body, yet awe still shimmered in his blue eyes.
By brushing that colossal Gate of Worlds he had learned the truth: when the Devil Fruit slipped between dimensions it stitched the shinobi realm to the seas of pirates—and because the fruit was the Door-Door Fruit, he could open that seam. The towering water-blue gate in his mind was the connection made visible, a doorway shaped by the Pirate World's endless ocean.
No wonder this fruit is called conceptual. Air doors, stone doors, wooden doors—fine. But a world-spanning door? That thought clenched his fists with giddy heat.
Compared to Konoha, the pirate seas promised freedom. Over there "monsters" were everyday folk—giants, fish-men, minks, long-arms, little people. In that crowd he would just be a normal boy, and with strength he could carve a name for himself—or at worst join the Marines and live safely.
The more he pictured it, the faster his heart drummed. He dove back into his inner world and shoved at the water gate…
Nothing. The portal, wrought from living surf, felt as heavy as a mountain.
Not enough power—no, not enough chakra. I can't force it open…yet.
He withdrew, teeth grinding. Since the fruit had fused with his bloodline, water never weakened him, proving it worked like a kekkei genkai. A bloodline limit needed no chakra to trigger, only stamina—still, when he'd pushed the gate it had budged a hair. Close, but not enough.
So I swallow my pride and build more chakra. Naruto exhaled, clamped his eyes shut, and resumed extraction. The sooner he left this hell called Konoha, the better.
Dawn bled through cracked shutters. Naruto opened weary eyes after a night of unbroken cultivation.
"Body's wrecked…" His stomach roared in protest. Prolonged refinement taxed spirit tolerably, but a five-year-old body could snap. Without nutrition he risked stunted growth—or instant collapse. No wonder the canon Naruto had been the shortest kid in class; junk food, spoiled groceries, and relentless chakra drain would cripple anyone not blessed with Uzumaki vitality.
I'm done eating garbage. Resolute, he pooled chakra into his palm and pressed the crumbling wall.
"Stone Door."
CREAK! A half-meter-thick slab folded outward like a hinge. The drain was laughably small—barely one-twentieth of his reserve. He could now open more than twenty doors in a row.
"Wooden Door."
"Revolving Door."
"Sliding Door."
"Folding Door."
"Invisible Door."
CREAK-CREAK-CREAK!
The shabby room became a showroom of impossible portals, each unique in frame and function. Naruto's grin stretched ear to ear as he imagined battle uses: traps, shields, shortcuts… Endless possibilities. Only when half his chakra was gone did he stop, stroking thin air.
"Air Door."
A translucent panel swung open. Unlike before, Naruto stepped through. Inside the Air Door was neither void nor ordinary space but a liminal pocket where he could see the outside world as though behind crystal glass—while his own body felt weightless, incorporeal, able to pass through walls like a ghost.
He studied the phenomenon until fatigue spiked, then slipped out through the apartment wall and into Konoha's bustling streets.
For the first time, not a single hostile glare met him; the villagers couldn't perceive the boy walking one layer sideways from reality.
So this is probably what Obito Uchiha feels when he's phasing, he mused, lips quirking.
He roamed unseen past familiar faces: Anko Mitarashi buying dango; Chōji and Chōza Akimichi demolishing barbecue; Might Guy sprinting upside-down on a log while shouting about youth. None sensed the blond specter drifting by.
At last he reached a grocer's storefront. Ignoring the proprietor, Naruto slid into a dark corner, extended one hand, and whispered:
"Air Door."
A palm-sized gateway popped open. Far too small for a person—but perfect for a hand. He slipped his arm through and swept whole shelves of food into the pocket beyond.
Soon his diet would improve—and with it, his strength.