"Chakra is still a kind of energy… so does it exist like particles?
And if that's true—does a fused ninjutsu mean different 'chakra particles' locking together and moving in some fixed pattern?"
Kenichi Amemiya stared at his notebook, half scientist, half philosopher.
The shinobi world used chakra to do everything: fight, heal, track, seal, summon, even resurrect the dead.
But for all that, almost nobody seemed to care what chakra actually was.
Just like his previous world: humans could fly to space, but still knew almost nothing about the deepest parts of the ocean.
He shook his head.
"Forget the theory rabbit hole for now. First problem: how do I get thermobaric fuel to hold chakra without exploding on contact?"
Until he solved that, his schema for "multi-nature chakra + fuel" was nothing but a nice concept.
And that required materials he didn't have out here.
Orochimaru's lab, however… definitely had what he wanted.
Specifically: the specialized paper used to make explosive tags.
Normal paper couldn't hold chakra, much less a pre-formed jutsu like Fire Release.
Explosive seals needed special treated paper capable of storing that power.
Kenichi had considered using chakra-conducting metal.
It would be ideal—durable, conductive, and reusable.
But there was a problem:
Chakra metal was expensive enough to make a daimyo cry.
If he could pull this off with seal paper instead, the cost would plummet. Mass production might actually become possible.
Of course, there was a reason explosive tags were expensive too:
First, they needed very fine chakra control to "write" Fire Release into the seal matrix.
Second, the paper itself required special processing to hold that chakra safely.
Still, if seal paper could hold fire-nature chakra, it was worth testing if it could hold sage chakra.
"If I can store senjutsu chakra in separate tags… then all I'd need is a synchronized trigger for three seals and shove them into the bomb."
Crude? Yes.
Dangerous? Absolutely.
Practical? If it worked, very.
He'd never seen Jiraiya or Naruto do something like this, though.
And those two were walking Sage Mode pamphlets.
Naruto just loved spamming Rasengan instead, like a blonde industrial mixer.
If sage-chakra seals were possible, Jiraiya should've made them already, right?
"So chances aren't great," Kenichi admitted. "But then again, this world didn't even invent hot air balloons until I showed up."
If the ninja world could miss something that basic, maybe it had missed this too.
It was worth a shot.
While Kenichi was planning to cram natural energy into flimsy pieces of paper, far away in Konoha…
A silver-haired man sat quietly in front of two gravestones.
Kakashi Hatake.
On one stone was engraved the name Uchiha Obito.
On the other, Nohara Rin.
Kakashi had another habit besides being late and pretending it was "on purpose":
Whenever he returned from a major mission or battlefield, he would come here.
He talked to the graves. About the war. About missions. About his squad. About the kids growing up in the village.
He knew the dead couldn't hear him.
But it still helped.
Like draining poison out of an old wound that never fully healed.
At least, he thought no one could hear.
He was wrong.
"…What is this?"
Hidden in the trees, Obito watched Kakashi quietly, his face half covered by a swirling mask.
He had every reason to mock Kakashi's "sentimental performance."
That's what he told himself, anyway.
But today, he didn't feel like mocking.
He just stared at that familiar face—
And those eyes.
Kakashi's left eye, the Sharingan Obito had given him.
Three tomoe, spinning softly.
But the longer Obito looked, the stranger his expression became.
That wasn't right.
It looked like the eye he'd given Kakashi.
But his instincts screamed that something about it was different. Off.
Like someone had taken his eye, copied its pattern, and put in a bootleg upgrade.
"What's wrong?" came a lazy, amused voice from the shadows.
Black Zetsu.
He hadn't wanted to come. But knowing Obito's personality, he'd worried the idiot might get soft, stare too long at the graves, and start questioning the plan.
That would ruin everything.
"…Nothing," Obito muttered.
He couldn't explain it. He just knew that eye wasn't exactly the one he'd left behind.
Complicated emotions twisted in his chest.
Guilt. Anger. Grief. Resentment.
He'd chosen to give Kakashi that eye. True.
But that didn't mean he could accept the idea that someone else might have taken it. Altered it. Used it.
"Status of the Fourth Mizukage?" Obito changed the subject abruptly.
"Still dancing on his own strings," Black Zetsu chuckled.
"His 'Blood Mist' policy is making plenty of enemies. Give it time. Let the hatred ferment. When the village is at its most unstable, stepping in will be much easier."
They could force control right now—over both the Mizukage and the Three-Tails.
But why do something messy and inefficient, when you could let a country rot from the inside and walk in at the perfect moment?
Obito nodded, then cast one last glance at Kakashi, silently talking to two empty graves.
He turned and walked away with Zetsu.
He didn't know who had touched that eye.
But now, he had suspicions.
And Uchiha Obito did not forgive easily.
Back in the Land of Rice Fields, Kenichi was lying in a chair, staring at the ceiling.
The sealing experiment had failed.
Spectacularly.
The moment he tried to infuse sage chakra into explosive-tag paper, it detonated on the spot.
If his reactions weren't ridiculous, half the lab equipment would be spare parts by now.
"Real pain in the ass…" He rubbed his temples. "So seal paper really can't handle senjutsu chakra."
Which meant plan A was dead.
Unless he wanted to rebuild the lab. Again.
"So that leaves only one realistic option: chakra metal."
He sighed.
Using chakra-conducting metal as a storage medium would work in theory. It could hold and channel nature chakra safely… probably.
But the cost would skyrocket.
And he wasn't even sure the concept was viable yet.
He'd be burning money to test a hypothesis.
Kenichi glanced sideways.
Several shadow clones were still busy in the lab—
cultivating seeds, logging data, recalibrating instruments.
Fortunately, research didn't drain much chakra compared to battle. His Sage Body gave him a massive chakra pool, and clones doing paperwork barely took a sip from it.
That was why he wasn't panicking about making so many of them.
He waved one clone over.
"You. Keep the fuel research log organized and cross-check the measurements. I need to step out and play… supervisor."
Because Orochimaru had just sent him a message through Pain:
"The construction team I ordered from the black market has arrived.
I've reassigned them to you.
Pick a location for your lab and have them build it."
Kenichi stared at that for a long moment.
"So Teacher just… dumped an entire underground construction crew on me and walked away?"
He let out a helpless laugh.
"Sensei, when did we become so formal? At this rate you're going to start sending me invoices for breathing the same air."
Of course he couldn't exactly go say:
"From now on, my lab is your lab, Sensei."
That would sound weird even by their standards.
Still, first-time site selection was important.
It'd be stupid to leave everything to strangers.
So he left the base and went to the rendezvous point.
Soon, he spotted them.
Fifty workers.
Four ninja acting as guards.
Faces hard, expressions dull.
Very typical "black market labor force" vibes.
Kenichi scratched his cheek and walked up.
The leading shinobi stepped forward with a very professional, very practiced smile.
"Hello. We are from Hidden Construction Company," he said politely.
Kenichi looked at the man, then at the crowd behind him, and felt a small grin tug at the corner of his mouth.
"Perfect," he thought.
"The Third Uncle who comes to fix doors… is finally here to build me a bomb-proof house."
Note: If you're interested, you can read up to chapter 99+ at patreon.com/nakai01. Don't forget to give a power stone for many bonus chapters.