**Outside Konoha Village in the Forest of Death**
Haruki stood by a stream. Streams of water seemed to consciously flow into the balloon in his hand, quickly filling it.
"Rasengan, simply put, is concentrating one's chakra in the palm, rotating it in random directions, and compressing it to form a non-elemental chakra sphere," Haruki explained as he tossed the water balloon to Minato Namikaze.
"In the first stage, make your chakra move randomly inside the water balloon until it bursts."
"Yes, Sensei," Minato replied, holding the water balloon, concentrating, and slowly injecting chakra into it. Under the faint glow, the liquid began to spin violently.
Haruki nodded.
Apart from bloodlines, Minato Namikaze's talent was undoubtedly exceptional. In the entire Naruto world, he was among the top. Unlike Naruto Uzumaki in the original series, Minato could perform decently after hearing an explanation once. This stage was likely to be completed quickly.
While keeping an eye on Minato's training, Haruki contemplated his next plans. His main occupation was teaching. Being a medical ninja, he seldom received dangerous missions, mostly working in logistics. Teaching at the Ninja Academy was far more interesting than working at the Konoha Hospital, gradually changing the students' mindset gave a sense of accomplishment.
However, Haruki wasn't content with just that. Education was a long-term endeavor, and it would take at least a decade to see results. Even the best education has its failures. Haruki thought of Orochimaru. His next plan depended on Orochimaru's research.
Three years ago, after meeting Orochimaru, Haruki had hinted at high school biology knowledge, sparking Orochimaru's interest. Following a friendly exchange, they reached a consensus. Haruki provided funds, knowledge, and various research ideas, and Orochimaru worked for him. Orochimaru could never have guessed that topics like immortality, cursed seals, and cloning were his original concepts.
But it wasn't a loss for Orochimaru. Despite being a scientist, Orochimaru's path was highly unconventional. With Haruki's guidance, he shifted his research to the essence of chakra.
As Haruki had told him, theoretically, learning all ninjutsu was impossible. But if one grasped the essence of chakra—how it's formed, what it's made of, why it changes nature, why it's divided into mental and physical energy—they could fundamentally understand all ninjutsu, mastering any technique, even potentially understanding bloodline limits.
A perspective Orochimaru had never considered, which enlightened him. He plunged into the embrace of science. As for becoming Hokage, Orochimaru said, "Hokage? What's that? It would only slow my research."
"I wonder how the research on the Caged Bird Seal is progressing?" Haruki hadn't visited Orochimaru's lab for a while and wasn't sure about his progress.
"Minato, don't slack off," he suddenly turned to see the panting Minato Namikaze.
"Sensei... I can't... I can't go on..." Minato, exhausted, sat on the ground. Despite his high talent compared to his son Naruto Uzumaki, he didn't have the Nine-Tails' chakra, making his chakra significantly less.
"A man shouldn't say he can't. Here," Haruki threw a paper box to him, then made a hand sign, and green chakra enveloped Minato, relieving his fatigue.
"Military Ration Pills?" Minato opened the box, recognizing the pills inside. He ate one, immediately replenishing his chakra.
Haruki glanced at him, seeing his renewed determination, and continued pondering the Caged Bird Seal. He had Orochimaru study it, not to remove it, but to adjust it. The Caged Bird Seal was originally to prevent the Byakugan from falling into the wrong hands, but over time, it became a tool for the main family to control the branch family.
Orochimaru was to change the control of the Caged Bird Seal from external to self-controlled. No matter how harmonious they appeared, no true brotherhood could exist when one had control over the other's life and death. The prime example being Neji Hyuga, the tragic genius.
Haruki saw great potential in the Byakugan. Though the difficulty of evolving it to the Tenseigan was immense, he believed the Byakugan held more strategic value than the Sharingan. Its auxiliary capabilities were excellent, whether in battle or medical use, far surpassing the Sharingan.
Having decided to reform Konoha, Haruki focused on the Byakugan. Besides using it for reconnaissance, he had two initial ideas: forming a special long-range unit, as the Byakugan was better than any telescopic sight, and using it for medical purposes, as it was akin to having an x-ray machine on hand.
Regarding the Hyuga Clan's Gentle Fist, while still effective in close combat, by the later stages of Naruto, battles involved enormous powers and abilities like Edo Tensei and White Zetsu armies. Gentle Fist could only do so much.
Lost in thought, Haruki periodically infused Minato with chakra, alleviating his fatigue. Minato grimaced. Although physically not tired and his chakra replenished by the Military Ration Pills, his spirit was worn out, feeling like a corporate slave working non-stop.
"What's wrong, Minato?"
"Nothing, Sensei," Minato replied, shaking off the feeling. It must be his imagination. Sensei was strict but meant well.
Throughout the day, Minato trained until he was dizzy, with Haruki continuously healing his fatigue.
"I did it!" Minato exclaimed at dusk, but quickly slumped, exhausted.
"That's enough for today. Rest well," Haruki said.
"Thank you, Sensei," Minato replied weakly.
"By the way, there's something you need to know. Prepare yourself," Haruki added, tapping his forehead, smiling.
Minato shivered, sensing something ominous. "What is it, Sensei?"
"You know, medical ninjutsu accelerates cell division, which shortens your lifespan."
"So, using medical ninjutsu just now consumed my lifespan?" Minato felt a mix of emotions.
"Of course not. I would never do that to you."
"Huh?" Minato's eyes widened, feeling ashamed for doubting his teacher.
"So, I used some techniques to trick your body, delaying the fatigue. If you experience any adverse effects tomorrow, it's normal."
"???"
Minato stood frozen. By the time he recovered, Haruki was gone. Hoping it wouldn't be too bad, Minato went to sleep. The next day, he almost ascended to heaven. His entire body felt foreign, overwhelmed by fatigue, soreness, and pain.