After completing another grueling training session, Sasuke sat down to recover his chakra. Each time, he would first use up his chakra, familiarizing himself with its application. When his chakra was depleted, he would then focus on training his body. For instance, if someone observed Sasuke doing push-ups, the first hundred would be executed with perfect form and rapid speed, all thanks to the enhancement of his chakra.

But once his chakra was exhausted, the speed of his push-ups would noticeably decrease, though each one was still performed with utmost seriousness. This training method, devised by Sasuke himself, allowed him to become more adept at manipulating his chakra and to strengthen his body purely when his chakra was depleted. By the end of each session, he could even recover a bit of his chakra before sitting down again to restore it fully.

Why replenish his chakra during physical training? Sasuke understood that a ninja must always retain some ability to survive. If he ran out of chakra during a battle and was still being pursued, he could rely on his physical strength to escape and gradually restore his chakra, allowing for a potential counterattack. Sasuke had no intention of becoming the type of ninja who was rendered useless once his chakra was spent.

Rising slowly, Sasuke massaged his legs, numb from sitting too long. He glanced around, surrounded by towering trees, as if he were in a primeval forest. The sunlight filtering through the leaves turned his face a golden hue, making him appear full of life. Sasuke had been here for nearly half a year, spending every day training with relentless determination, only returning home to eat and sleep. It had been almost two years since Sasuke had acquired the basic ninja arts, and he had just celebrated his third birthday a few days ago. Half a year ago, to avoid distractions during his training, Sasuke had sought out this forest, known as the "Forest of Death."

"These days, my chakra hasn't increased at all," Sasuke sighed.

"Have I hit a bottleneck? Am I too young for this? It seems my three-year-old body can only contain so much chakra," Sasuke mused. "I'll have to think hard about how to solve this problem when I get back. If I can't find a solution, I'll just have to wait until my body grows."

He shook his head in frustration, gazing at the sky. Realizing that dusk had fallen and his chakra was fully restored, Sasuke clapped his hands and prepared to head home.

After all, this was the Forest of Death—no one could predict when danger might strike, especially at night when it was even more perilous. Just a few days ago, Sasuke had heard wolves howling, a reminder that sooner or later, the wild beasts would discover his presence. If it were only beasts, Sasuke wouldn't be worried—after all, he was a genin. But the Forest of Death housed more than just wild animals; it was teeming with ninja beasts, some stronger than even the most skilled ninjas. The fact that Sasuke hadn't encountered one yet was merely a stroke of luck.

It seemed Sasuke's luck had run out. Just as he was about to leave, he distinctly heard the sound of a branch snapping underfoot. Though faint, Sasuke's senses picked it up immediately, or perhaps he heard it. He halted his steps and swiftly leapt onto the nearest tree branch, steadying his breath and quieting his movements, concealing his presence. This stealth technique was one of the basic ninja arts, though it hadn't been mentioned earlier. Naturally, it was covered in the basic ninja arts book. However, this technique was so basic that it was practically useless; every ninja eventually developed their own methods of concealment, rendering the basic version obsolete.

Nevertheless, Sasuke concealed himself like a true ninja. Ninjas were assassins, not warriors. The goal was to hide, observe, and strike when the enemy was weakest or most exhausted, finishing them off in one swift blow, avoiding drawn-out battles. Even a novice like Sasuke knew that the simplest way to defeat an opponent was to use the least amount of energy, not waste chakra and stamina on unnecessary large-scale jutsu.

Slowly, Sasuke reached into his bag and retrieved his weapon, a kunai—a prize he had swiped from Itachi's room. The kunai was already showing signs of wear from extensive use. Sasuke had practiced with it over the past six months, preferring the feel of a real weapon over a replica. One side of the kunai had become completely dulled, though Sasuke would sharpen it against stones to restore its edge. But it was clear that this kunai was nearing the end of its usefulness. Unfortunately, it was the only kunai Sasuke had, so he would have to use the other side in battle.

The sound of movement grew louder, signaling the approach of Sasuke's first opponent. He dared not use his chakra to sense the presence of his adversary, unsure if it was a ninja or a ninja beast. After all, Sasuke had trespassed into the Forest of Death, and it would not be good to be discovered by a Konoha ninja. If the opponent was a jonin or chunin, it would be easy for them to detect the chakra of a novice genin like Sasuke. Sensing chakra to determine whether the opponent was a ninja was common practice, but Sasuke was no fool; he knew better than to use chakra when he had no idea of his enemy's level.

Gradually, Sasuke's first opponent came into view. It wasn't a person, but a bear. Judging by its size, it was a fully-grown ninja bear. Most bears weren't this large—Sasuke estimated it to be over three meters tall, weighing at least three tons. For someone like Sasuke, who had only trained but never engaged in actual combat, this opponent posed a real challenge. Bears, in Sasuke's mind, were immensely strong but slow-moving and poor-sighted. This would be a perfect opportunity to test his skills.

With that thought, Sasuke regarded the bear as his training target. Fortunately, the bear hadn't noticed him yet. Using its sense of smell to track a ninja's location was beyond this bear's capability. The basic concealment technique was more than sufficient to evade detection by a bear, even a ninja bear, which was likely one of the lowest-ranking ninja beasts. Despite Sasuke being only a genin, he was confident he could defeat the bear.

The best strategy Sasuke could think of was to channel his limited lightning-nature chakra into the kunai, making it more penetrating. In one powerful throw, he would aim for the bear's vital spot, ending its life in an instant. However, this method wouldn't allow Sasuke to fully gauge his strength, so he decided to engage the bear in direct combat, even switching to a wooden kunai he had made himself.

With chakra gathered in his feet, Sasuke sprang into action. At that moment, the bear finally noticed him, standing upright. Bears were known for their tremendous strength, so Sasuke made sure to keep moving, preventing the bear from locking onto his position. However, Sasuke underestimated the bear's power and overestimated his own.

As Sasuke changed direction, the bear let out a deafening roar that rattled Sasuke's eardrums. It raised its forelimb and swiped at Sasuke, striking the air where he had been. With a loud "boom," Sasuke's body turned into smoke, replaced by a log. "Substitution Jutsu." The log that had saved Sasuke was shattered into splinters by the bear's mighty paw, making Sasuke realize the danger he was in. "I mustn't let that bear touch me, or I'll lose my life here."

Though chakra could cushion an attack, Sasuke decided it was best not to take unnecessary risks.

Once again, Sasuke infused his feet with chakra, moving at his maximum speed, as if he were in a training session. In a flash, he was in front of the bear. Just as the bear raised its forelimb to strike again, Sasuke leaped into the air, causing the bear's attack to miss.

After observing the bear's movements, Sasuke noticed that the bear put all its strength into each attack, causing it to momentarily lose balance. In Sasuke's mind, this was the perfect opportunity!

As he leaped, Sasuke channeled his chakra into the kunai, willing it to become sharper, more lethal. The kunai began to glow with a faint light, a sign that Sasuke had not yet fully mastered the lightning chakra nature transformation, but it would be enough to deal with this bear.

In the blink of an eye, Sasuke threw the kunai with all his might, aiming for the bear's left eye. Off-balance, the bear couldn't avoid the attack. With a sickening "thud," the kunai pierced through the bear's eye and continued through its skull, embedding itself in the tree behind. The bear collapsed, lifeless.

Retrieving his kunai from the tree, Sasuke sighed and said to the bear's corpse, "I wanted to test my strength on you, but you posed too great a threat. I'm sorry, but I had to kill you first. It seems I'll have to find another way to measure my true power."

Instead of feeling displeased, Sasuke was elated. The sight of the bear's blood did not frighten him. In his previous life, Sasuke had taken lives, and this new act of killing brought back that same exhilarating feeling. "It seems I really am cut out to be a butcher," Sasuke muttered to himself.