After dinner, Xia Ji returned to his room, shutting the door behind him. He pulled out the thin, worn book on chakra extraction and settled down to read. In his previous life, he had never studied this diligently — not even close.
He already understood the basics of chakra. Or rather, he understood the theory. As for actually extracting it? That was another matter entirely. He had once wanted Sinai to teach him, but she had only shaken her head.
She still retained the ability to use chakra, yes — but the detailed knowledge, the techniques, had been returned to her former teacher. More importantly, Sinai had warned him against even trying before the age of six. Extracting chakra too early, she had said, could affect a child's body in unpredictable ways.
And she wasn't wrong. Chakra was, after all, the fusion of physical energy and spiritual energy. To extract it was to tug at the balance between mind and body — and the body of a child was still in the process of growing.
From what Xia Ji understood, mental energy determined how much chakra could be extracted at a time, while physical energy determined the total stock one could hold. Only when the two were combined could usable chakra be formed.
Physical energy itself was influenced by two things — physical fitness and bloodline. Physical fitness could be trained and improved over time; bloodline, however, was fixed from birth.
For ordinary people, the bloodline coefficient was depressingly low, which meant they needed exceptional physical fitness just to maintain a decent chakra reserve. On the other hand, those blessed with special bloodlines — like the Uzumaki clan — had absurdly high coefficients. Even without top-tier physical training, they could hold massive reserves of chakra.
Bloodline also affected recovery speed, though that mattered far less in most fights. In real battles, winners and losers were often decided within a few exchanges. A quick recovery was a nice bonus, but not a deciding factor.
Still, Xia Ji couldn't help wondering if there were any treasures in this world that could improve one's bloodline coefficient. After all, in cultivation worlds, there were always strange herbs and mythical beasts that could refine the very roots of a person's potential.
Here? Not so much. Sure, there was the so-called Dragon Vein, but he couldn't remember exactly when or where it appeared — and even if he did, it might not align with his goals.
Cells from the First Hokage? No thanks. Living as some half-human, half-ghost monstrosity wasn't his idea of a good time. Sealing a tailed beast inside himself? Equally unacceptable. He wanted to grow to his peak in his own body, as a human, without outside gimmicks twisting him into something else.
His ambitions weren't lofty — survive, grow stronger, and never become cannon fodder. That was enough.
With a quiet sigh, he closed the book. In this world, the only way to grow was to rely on yourself… and maybe, if you were lucky, stumble into a little "mutation" along the way.
"Mom, I'm going out," he called.
"Come back early, and be careful," Sinai replied from the kitchen. She was already used to Xia Ji heading out daily. She'd assumed he might take a break after school today, but it seemed not.
It wasn't playtime he was after. Physical strength formed the foundation of chakra reserves — and if he wanted to avoid running dry after a few jutsu in the future, he needed to keep training.
Realistically, his current body — even with months of exercise — was only on par with an ordinary second-year student. Still, he had noticed a gradual improvement lately. Maybe it was just age catching up with his training, but either way, it meant he could try pushing a little harder.
Of course, he had to be careful. At six years old, his body was still in its growth phase. Overtraining could cause long-term damage. Testing his limits once or twice was fine, but squeezing himself dry would only slow him down in the long run.
Today, however, he planned to experiment — to see just how far he could go.
The training grounds he slipped into were tucked away and usually quiet, but as expected, someone was already there.
Xia Ji knew him well. Every time he came, this boy was already deep into his workout, and every time he left, the boy was still at it.
Rock Lee — the so-called "hardworking genius."
Even from a distance, Lee's dedication was obvious. Xia Ji suspected that his own theoretical potential might be higher, but in the real world, growth periods were short. With Lee's insane work ethic, catching up was… unlikely.
"Oh! Xia Ji! You're half an hour late today," Lee greeted, eyes shining. "That's a penalty! Several extra sets for you!"
"…Fine," Xia Ji replied calmly. He had planned to push himself anyway.
Lee blinked, stunned for a moment — then his eyes lit up like a bonfire. "You agreed?! This… this is youth! I'll reward myself with even more sets today!"
Xia Ji couldn't help the faint twitch of his mouth. No matter how many times he saw it, Lee's enthusiasm was… something else.
They began. While Lee threw himself into high-intensity drills, Xia Ji stuck to his own, more controlled routine. He favored exercises that wouldn't stunt his growth, pushing his limits only in measured bursts.
Minutes bled into hours. Even at his lower intensity, Xia Ji was panting heavily, sweat running down his face. His muscles screamed for rest, but his spirit was still steady.
Lee's gaze burned even hotter. "Yes! Push through it! That's youth!"
With a deep breath, Xia Ji forced his movements to smooth out again, riding the rhythm of his body past the pain. Lee actually teared up watching him.
Finally, Xia Ji stopped, chest heaving. "Hah… looks like my limit's a bit higher than I thought." Not the true limit, perhaps, but the highest he could safely endure at his current stage.
They parted ways soon after. Xia Ji's steps were heavy on the walk home, but his mind was sharp. A quick rest, and he'd be ready to dive back into his chakra studies.
The next morning, he woke feeling surprisingly fine — which, naturally, meant he tried to push himself again.
On the third day, his body revolted. The lingering fatigue forced him into lighter training. Clearly, while breaking through limits was possible, it needed proper spacing.
Physical training and chakra cultivation… both were slow, grinding paths. Xia Ji exhaled, looking up at the morning sky.
Well, no one ever said it would be easy.