Ever since Naruto learned how to refine Chakra, he kept coming to the grove by the river to punch trees every day.
After doing it for several days in a row, it had practically become a habit.
Even when he wasn't fully awake in the morning, his body would automatically walk itself over to the grove by the river.
By the time he came to his senses, he'd already started pounding the tree with a bang bang bang.
The only pity was that he still hadn't made any real progress with the Shadow Clone Technique.
In his previous life, whenever he saw Shinobi use shadow clones in anime, they made it look effortless.
But now that it was his turn to learn it, he realized it wasn't just about memorizing the Chakra Flow Path inside the body… he also had to control the precise amount of Chakra output.
Using too much or too little Chakra will affect the success rate of the technique.
And the one with the greatest impact was the big fox in the sealed space...
Even though Kurama had been restraining his Chakra, some of his red Chakra was still mixed with Naruto's blue chakra.
This resulted in the amount of Chakra Naruto originally inputting was just right...
Kurama's Chakra would always be pulled in from time to time.
It was because of this that the last few times Naruto used the Shadow Clone Technique, the clones that appeared had completely broken limbs and was also unconscious.
It's even more miserable than what Naruto created in the original work.
In the next few tries, Naruto learned his lesson and deliberately reduced the amount of Chakra he used…
But that red Chakra was completely unpredictable!
Sometimes it showed up. Sometimes it didn't...
He now finally understood why Naruto in the original work had such a hard time...
The big fox may not have been causing trouble on purpose.
It's simply because the Biju have too much Chakra. Even a little bit of Chakra leaked is enough to disrupt the Chakra of a Jonin.
The fact that Naruto could even attempt Ninjutsu under these conditions, success or not, was already incredible.
Naruto tried to comfort himself with that thought, but deep down, he was still pissed at the big fox.
Especially since the stupid furball hadn't stopped laughing the entire time Naruto was practicing Shadow Clone Technique!
As he listened to the non-stop cackling and looked at the half-upper-body and half-lower-body clones lying on the ground, he couldn't hold it in anymore.
"Big Fox! Can you stop laughing already?!"
"It's all your fault I can't get this right!"
"Hahahahaha!"
"I've never seen clones this funny in my life!"
Kurama completely ignored Naruto and kept laughing like a maniac.
Naruto was so angry that he started practicing the Shadow Clone Technique out of pure spite.
Anyway, his Chakra is enough for him to practice for a full day and night!
In his previous life, he could grind out a plan or project for several days straight, so he didn't believe that he couldn't deal with a 'small' Shadow Clone Technique!
And so, the grove echoed with constant 'bang bang bang' sounds as clones appeared and vanished again.
Naruto failed again. And again. And again.
When Kurama, who is in the sealed space, saw how hard Naruto was trying, he eventually stopped laughing.
By the thousandth attempt, Naruto finally managed to produce a somewhat normal-looking clone...
Although it looked more like a mini version of himself, it was still a step in the right direction.
He then performed the Shadow Clone Technique's hand seal five thousand times. At the five thousand and first time, a spark suddenly flashed through Naruto's mind and he suddenly realized.
'Since the Biju's Chakra is disrupting my output...'
'And the Shadow Clone Technique requires a fixed amount of Chakra...'
'Then if I calculate the exact amount needed for the technique, and then factor in the variable amount of red Chakra leaking through, I can just add the two together to get the right total!'
'The scroll given by that old man Sandaime did not mention how much Chakra was needed to use the Shadow Clone Technique.'
'It just explains the Chakra Pathway, the hand seals, and a brief note on the shadow clone… then nothing else.'
'If one wanted to learn a Ninjutsu, they have to keep trying over and over again until they find the minimum amount of Chakra required for it to activate.'
'If that's not trial-and-error-based learning, then what is?'
Naruto figured that probably most Ninjutsu in the Shinobi World worked like this, basically a whole lot of 'I think this might work…' kind of vibe!
'Those Shinobi who tried to learn Ninjutsu were completely through a process of trial and error, and those who succeeded less often ended up being called geniuses.'
'No wonder why Naruto in the original work taught Konohamaru Ninjutsu in that way.'
'The fact that Konohamaru actually managed to learn it meant that kid was a genius.'
'Overall, the whole thing felt like one of those recipes that just say 'add a pinch of salt', or like the vague, mystical descriptions of martial arts techniques in wuxia novels.'
'It was all about the abstract.'
"Hey, Big Fox!"
"Does Chakra have any kind of unit of measurement?"
Although in the anime, Kakashi had once compared his Chakra to Naruto's, and fans joked about using him as the official Chakra Unit…
But that was just a meme, and at the end of the day, even that kind of comparison was just experience-based guesstimation.
Naruto was worried that Kurama wouldn't understand, so he simplified it even further.
"It's... something that calculates Chakra."
"For example, how much Chakra is needed to create a shadow clone."
When Kurama heard this strange question, he blinked in confusion, 'Why would anyone need to know that?'
Kurama had so much Chakra he never had to worry about running out, so why would he ever bother measuring it?
However, Kurama began to recall the situation of Hashirama and Madara, as well as all the Shinobi he had encountered over the years, and finally found that no one had ever cared about this.
"What do you need that for?"
"I've never met anyone who gave a damn about it."
'Okay...'
'The case is solved!'
After Naruto realized this, his expression became very strange.
'The Shinobi World has been developing for at least a thousand years, right?'
'So why aren't there any unified standards for Chakra?'
'No wonder there has been no progress at all.'
'In the later period, everyone was pinned to the ground and beaten by the Otsutsuki Clan. They deserved to lose.'
'Unacceptable!'
Now that Naruto knew this, he was determined to come up with a standard Chakra Unit.
In this way, when he learns Ninjutsu in the future, he can learn it quickly by just trying little by little according to the fixed amount.
'Having a Chakra Unit would allow for standardized training, effectively turning Ninjutsu into a more data-driven discipline.'
'It's probably many times better than the current 'feels about right' method everyone was using.'
After thinking it through, Naruto stopped practicing the Shadow Clone Technique and went back to lie down by the big tree.
Kurama was still confused about what Naruto was doing, and then he saw him appear in the sealed space.
"How should I go about this…"
Naruto stroked his chin and wandered through the orchard inside the sealed space while deep in thought.
When he passed by an apple tree, he noticed a ripe fruit dangling right by his mouth and casually took a bite.
Crunch crunch…
As he chewed the fruit slowly, he raised his head at a 45-degree angle to look at the sky and began to think.
Suddenly, Naruto's eyes locked onto the light on the top of the sealed space.
"I've got it!"
"We can use the number of light bulbs to represent Chakra Units!"
All the lights in the system interface, including all lighting items in the mods and items that require energy to work, could serve as a reference.
Because none of those items specifically required electricity. They just needed some kind of energy.
And logically speaking...
Chakra should also be a kind of energy, right?