Nighttime, Training Ground Three.
Thud.
With a dull thud, Sasuke-kun fell heavily from the tree trunk once again. This was already Sasuke-kun's countless failure; his body was covered in dirt, and his elbows and knees were covered in scrapes.
"That's enough for today."
Naruto walked over from a distance, carrying three large bottles filled with an amber liquid.
"Too much is as bad as too little. Your body has reached its limit; drink this."
Naruto handed the bottle over and said mysteriously, "This is my exclusive secret medicine."
Secret medicine?
Sasuke-kun was stunned, and the doubt that had plagued his mind for a long time seemed to have found an answer. No wonder he improved so quickly; it turned out he had medicinal assistance! He took a bottle, and after unscrewing the cap, a fresh scent of tea wafted out. Sasuke-kun's brow furrowed slightly.
"Black tea?"
With suspicion, he took a small sip. In the next second, Sasuke-kun's brow relaxed. As the cool liquid went down, an unprecedented sense of tranquility instantly smoothed out his long-strained nerves. Ever since the Night of the Clan's Massacre, Sasuke-kun's mind had been constantly filled with blood and screams. It had been a long time since he had experienced this kind of mind-clearing peace.
Not only that, but even the muscle soreness from the training just now had dissipated quite a bit. And vaguely, Sasuke-kun felt his Chakra increase by a tiny, almost imperceptible amount. Sasuke-kun was greatly shocked.
Because Naruto's Chakra reserves were so massive, he had never felt the slight increase in Chakra brought about by the improvement in mental energy. It was like adding a few drops of water to a pond—completely unnoticeable. Although Sasuke-kun was stronger and had more Chakra than his peers, overall, he was still at a level where he could clearly feel a slight increase in his reserves.
If it could be accumulated over time, there would surely be a significant improvement. Sasuke-kun became even more certain in his heart that this was why Naruto had improved so rapidly during this period. Besides mastering a more advanced training method... the most important point was this secret medicine of his!
A drug like this that could bring such improvements—increasing Chakra, restoring physical strength, and calming stray thoughts—as long as the side effects weren't too extreme, it was a priceless treasure. Sasuke-kun gripped the bottle, his gaze toward Naruto becoming complicated.
This guy... he's actually letting me drink such a precious thing so casually?
"Naruto, I hope you won't regret it too much when you're surpassed."
At the thought of this scene, the corners of Sasuke-kun's mouth couldn't help but curl up; the advantage was his! But then he thought that such a precious secret medicine must be quite expensive. Naruto was an orphan; even with relief funds, he certainly couldn't afford enough for two people. As a proud member of the Uchiha clan, he couldn't bring himself to get things for free.
So Sasuke-kun fumbled around in his robes for a while.
"Catch."
He tossed a wallet to Naruto; it was quite bulging. Naruto caught it and opened it. Good grief, there were about thirty thousand Ryo in banknotes.
"Give me a portion of that secret medicine every day from now on. If you need money, just tell me."
Sasuke-kun put his hands in his pockets, acting like a wealthy person who didn't lack money. Although the clan was gone, the inheritance left by the Uchiha family was enough for him to squander for several lifetimes. Naruto pulled out the money and threw the wallet back.
"Deal. The money inside is about a month's worth," Naruto said.
In truth, while Naruto's life couldn't be called wealthy, he didn't lack money either, and he didn't really care about it. In Naruto's view, as long as there was enough money to spend, it was fine. Previously, his life seemed poor mostly because he had nowhere to spend his money, not because he didn't have any. This problem wasn't alleviated until he learned the Henge no Jutsu.
Naruto, who already had a deep understanding of Sasuke-kun, took the money solely to ease Sasuke-kun's psychological pressure—to keep him from being suspicious or even refusing out of pride. That would instead slow down the rate of his improvement, thereby slowing down the rate of feedback for himself. Only by establishing a transactional relationship would Sasuke-kun drink it with a clear conscience. Naruto had really gone to great lengths for Sasuke-kun's sake.
"Come find me when you've mastered Tree Climbing; I'll teach you a Hiden technique."
Seeing Sasuke-kun about to start climbing trees again, Naruto stopped him.
"A Hiden technique?"
Sasuke-kun became even more energized upon hearing this and intended to continue training.
"Not only that, but to coordinate with the absorption of the secret medicine and improve training efficiency... I also have a set of strict routine requirements," Naruto raised a finger and said seriously. "Drink hot milk before bed, do twenty minutes of calisthenics, and get eight hours of sleep."
"Huh? What kind of joke are you playing!" Sasuke-kun said angrily.
He felt Naruto was insulting his intelligence. What kind of old lady's health regimen is this? I want to get stronger, not retire!
"Don't be so quick to refuse," Naruto interrupted him expressionlessly. "You should know that maintaining a good routine and getting enough sleep are great aids to training. You wouldn't want your Chakra refining efficiency to drop because of a lack of sleep, would you?"
Sasuke-kun's face turned beet red. After struggling for a long time, he finally squeezed out a single sentence:
"...Damn it!"
Although it sounded like nonsense, Naruto's current strength was living proof. And... what if? Besides, even if he didn't do it, how would Naruto know?
"For the next month, if you don't complete my requirements... even if you learn to climb trees, I won't teach you the Hiden technique," Naruto said slowly, looking at the unruly Sasuke-kun.
"You bastard!!" Sasuke-kun was clearly defiant.
"Don't think about slacking off. While you're watching me, I'm also watching you. So, don't forget to buy milk in a bit."
Naruto patted Sasuke-kun on the shoulder and turned to leave, hiding his merit and fame. Leaving only Sasuke-kun standing there, still debating whether or not to go buy milk. He now felt as if he was being played like a fiddle by Naruto...
Late at night, at Naruto's house.
The curtains were closed, and the only light in the room came from the faint glow of a desk lamp. Naruto sat at his desk, toyed with the empty teacup in his hand, and frowned slightly.
Sasuke-kun still needed time to grow. But in the face of the massive mental load of future Kage Bunshin, this rate of growth still seemed like a drop in the bucket. Naruto pushed up his glasses, his eyes calm.
"If I could find a way to directly train mental energy or optimize the brain's carrying capacity..."
Although the Shinobi World also had methods for training mental energy, most were held by the Yamanaka clan or Genjutsu clans and were considered closely guarded secrets. Since he couldn't find it in Konohagakure for the time being, he would look further afield.
With a thought, Naruto opened the [Heavens Forum]. The forum was as bustling as ever. Various strange posts floated on the homepage:
"I turned a zombie into a Jiangshi, and my master said I'm messing around. Does this count as innovation?" "Shocking! Does cross-dressing help you get stronger? On the correct way to become a Magical Girl..."
Naruto skillfully ignored these fluff posts, edited a title, and clicked send.
[Discussion: How to effectively increase the limit of mental energy?]