So, this was how exhausting training could be.
After finishing his run, Naruto lay under a tree like a drowned rat, gasping for breath. His usually refined image was completely gone; right now, he was a mess. He hadn't fallen into a river – all the moisture soaking him was his own sweat.
Naruto had originally thought training was about learning various combat techniques, and that with talent, learning would be twice as effective with half the effort. He hadn't expected that the solid foundation required for training could only be built through an accumulation of time and physical exertion.
'Do I regret this?' he asked himself internally.
'No. I am resolved to become stronger.' He shook his head, casting aside these turbulent thoughts.
"The human physique is frail, yet it is also malleable. Through training, they can possess limitless possibilities," Aizen mused, watching Naruto's training with a glint in his eyes.
Among humans, there were indeed those strong enough to rival Shinigami; they were called Quincy. The fundamental difference between them and Shinigami was that Shinigami continuously increased their own Reiatsu through cultivation, while Quincy could directly draw Reishi from the external environment. This also meant that, with the exception of a very few exceptionally talented Shinigami, most Shinigami improved their strength much more slowly than Quincy.
This sparked jealousy among the Shinigami, but it wasn't the primary reason for the outbreak of conflict. The most critical difference lay in their attitudes towards Hollows. When Shinigami killed Hollows, they merely purified their souls, allowing them to re-enter the cycle of reincarnation – after all, Shinigami themselves were converted from human souls. Conversely, Quincy would completely eradicate a Hollow, destroying its soul. Therefore, the actions of the Quincy would disrupt the balance between Soul Society and the World of the Living, potentially leading to the Shinigami's extinction.
Thus, war erupted between the two. In the bloody war that lasted for a thousand years, the Quincy were steadily defeated, nearly wiped out by the Shinigami. In the current World of the Living, Quincy were almost never seen.
Unlike those Shinigami who loathed the Quincy, Aizen was filled with curiosity about them. If the potential of both humans and Shinigami had an upper limit, then what about a union of human and Shinigami? It was precisely because of this that Aizen had, not long ago, orchestrated the birth of Kurosaki Ichigo, a boy possessing both Shinigami and Quincy bloodlines.
A sense of anticipation filled Aizen at this thought. One was the offspring of a Shinigami and a Quincy, and the other was a human possessing the powers of both Shinigami and ninja. He wondered just how great a surprise they would provide him.
"The Nine-Tails Jinchuriki has begun training," an ANBU agent reported Naruto's activities to the Third Hokage in real-time.
"Training? Why would Naruto suddenly think of training?" The Third Hokage frowned deeply, taking a hard draw from his pipe. He took out his crystal ball and began to monitor Naruto's every move.
In the crystal ball, Naruto was currently carrying a sizable tree. The roots still had soil clinging to them, clearly freshly uprooted. It was about as tall as Naruto and had to weigh at least fifty pounds. Seeing Naruto struggling yet still pushing forward, the Third Hokage's brow twitched.
"It seems I need to do something."
Naruto had initially thought this kind of self-abusive training would damage his body. Strangely, however, after a night's rest, his sore body would recover completely, and he'd be as energetic as ever.
'My recovery rate is extraordinary,' Naruto thought.
With this assurance, Naruto continued his high-intensity training. At first, there was some resistance, but training was like lifting weights – the soreness and pain eventually became a familiar, almost enjoyable sensation of pushing his body to its limits.
Then, one night, the Third Hokage arrived unannounced.
"Naruto, how have you been? I forgot to give you your living expenses last time I came by." The Third Hokage placed a wad of money on Naruto's table.
"Grandpa Hokage, this is too much!" Naruto quickly counted it, his face lighting up with pleasant surprise. This allowance was at least fifty percent more than usual. He could afford slightly better ingredients this month.
"Consider the extra part a little pocket money from your grandpa." The Third Hokage winked at Naruto. Each with their own hidden thoughts, they exchanged a smile.
Sarutobi: So easy to control.
Naruto: Heh.
At that moment, the Third Hokage pretended to just notice Naruto's fatigue and asked with concern, "Naruto, why do you look so tired?"
"I've been training these past few days, so I've used up a lot of energy," Naruto replied, going along with it. The two then expanded on this topic.
"Why did you start training?"
"Because only by becoming strong can I become Hokage! I want to have the power to protect everyone."
Hearing Naruto's textbook answer, the Third Hokage was inwardly moved. He took several hard puffs from his pipe but quickly remembered Naruto was still a child, so he put the pipe down and said with considerable emotion, "Naruto, you've really grown up."
"Perhaps it's my environment. Because I yearn for acknowledgment, I think about many things," Naruto said, his expression momentarily downcast. But he quickly looked up, a bright, warm smile spreading across his face. "I believe I can become Hokage!"
"If there's anything you need my help with, don't hesitate to ask," the Third Hokage promised.
Naruto seized the opportunity to request instruction in swordsmanship and chakra control.
"You're already four years old; it's about time you started refining chakra. I'll have the ANBU send you some basic books. But why swordsmanship, I wonder?" Ninjas excelled with kunai and ninjutsu. Those who used swords were few and far between.
"A few days ago, I read about the White Fang in the 'Legends of Konoha Heroes.' I think that if one's swordsmanship is superb, it can also play a crucial role in battle," Naruto replied, having prepared his answer.
"Why insist on swordsmanship? Proper use of ninjutsu can be just as deadly. Besides, practicing swordsmanship requires a great deal of time, doesn't it?"
"Actually… I just think swordsmanship is cool, and I want to try it," Naruto said, scratching his head sheepishly.
Children this age really did want to be both cool and strong. The Third Hokage remembered having similar thoughts in his own childhood. He'd see a cool-looking attack style and want to learn it, only to give up after trying. He believed Naruto would likely abandon it soon enough too.
Thus, the Third Hokage readily agreed to Naruto's request.
After the Third Hokage left, Naruto closed the door and took out the Asauchi from under his bed. The plain, jet-black Asauchi glinted coldly, like a blade thirsting for blood.
"An Asauchi is the form a Zanpakuto takes before it awakens. It will only awaken after the Shinigami communicates and merges with the sword spirit," Aizen stated at that moment.
"Sword spirit? What's that?" Naruto looked bewildered. "Awaken the Zanpakuto?"
Naruto stroked the Asauchi, and once again, a faint connection formed between his heart and the blade. This feeling was…
Naruto's eyes widened. That heart-pounding, soul-deep connection was so familiar.
Suddenly, an intense wave of fatigue washed over him. Naruto felt his eyelids grow heavy. Clutching the Asauchi, he leaned against his bed and fell into a deep sleep.