The next few days were filled with intense focus as Haruto pushed the boundaries of his learning. He was only scratching the surface of Thunder Arc, a lower-tier A-rank jutsu, and though it remained largely theoretical, the challenges were clear. Shaping lightning chakra into a whip-like arc capable of striking with precision or even deflecting attacks required incredible finesse. This wasn't just about releasing raw energy—Haruto had to control its length, maintain its intensity, and direct its movement without losing control. It was like trying to guide a bolt of lightning through a narrow path.
His shadow clones made the training more efficient. Each clone, capable of splitting its focus the same way Haruto could with his two-minds ability, effectively multiplied his progress. Every attempt at summoning the arc brought new insights. The whip flickered in and out of existence, sometimes too short, sometimes too long, but with each flicker came understanding. The jutsu required an almost intuitive control over the fluctuating nature of lightning chakra. Haruto wasn't yet close to mastering it, but small experiments with the whip gave him valuable data. Theoretical progress, step by step.
Yet, despite his mental control over the chakra, Haruto knew his chakra reserves weren't enough to sustain this jutsu for long. In a real fight, he'd be hard-pressed to maintain Thunder Arc, but for now, it served as a glimpse into his future potential. Haruto's mind was already busy imagining ways to incorporate the arc into his Thunder Scalpel, to give the scalpel more reach and power. He could see it—how they could merge into something deadlier, something capable of range and precision. But that was for later. Now was the time for patience and small steps forward.
Beyond this, another project consumed his thoughts: his body.
At ten years old, Haruto was still slight, his frame wiry despite his rigorous training regimen. He wasn't worried—puberty hadn't come yet. He knew he had two, maybe four years before his body would start its rapid growth phase. But that was the point. Haruto didn't plan to wait and let nature take its course. He wanted to take control.
His plan was ambitious: using medical ninjutsu, Fuinjutsu, and even the knowledge he carried from his old world, Haruto wanted to reinforce and accelerate his body's natural growth processes. Most shinobi accepted their development as it came, pushing through workouts and missions to let their strength come naturally over time. But Haruto was never one to simply accept the pace of things. He wanted to go further, to make sure his bones, muscles, tendons, and organs would not just grow, but thrive beyond their natural limits.
His approach was theoretical for now, with only small, controlled experiments to test the waters. Medical ninjutsu was the first key. Haruto could already stimulate his cells using chakra, blasting them with controlled energy to enhance regeneration and promote growth. But simply pushing his cells too hard could cause more harm than good, so Fuinjutsu became the second key to his plan.
Fuinjutsu allowed Haruto to carefully design seals that could monitor and release the medical chakra in small, calculated doses. These seals would control the flow of medical chakra into specific areas of his body—his bones, muscles, tendons, and even his vital organs. The goal was simple: to accelerate natural growth without destabilizing his internal systems.
The process of strengthening his bones involved careful manipulation. The seals would stimulate the production of osteoblasts, the cells responsible for creating new bone tissue. Over time, his bones would grow denser, more resistant to damage, but it was a gradual process. He couldn't afford to rush it, not with something as fragile as his skeletal structure.
His muscles and tendons were more straightforward, but no less delicate. After intense workouts, Haruto would apply the seals to his muscles, using medical chakra to enhance their recovery and growth. Each session would help his muscles grow back stronger, faster, and more resilient than they would have through ordinary healing.
The most challenging aspect of the theory was his internal organs. His heart, lungs, and liver were vital to maintaining his stamina and overall health during increasingly intense training. Reinforcing these organs required a light touch. Haruto couldn't afford to overload them, but he could use the seals to gradually improve their endurance. His heart would need to handle greater blood flow, his lungs would need to pull in more oxygen, and his liver would have to process toxins faster as his body grew stronger. These were the long-term goals, but the path there was slow and deliberate.
None of this was easy be theorized. In fact, it would be painful. The stimulation of his cells wasn't gentle—it forced them to adapt rapidly, bringing waves of discomfort that sometimes bordered on outright pain. His body feel as if it were being put under a microscope, each part of it forced to work harder than it had been designed to.
But Haruto had a secret weapon: his tier 2 stamina recovery. Most shinobi would need rest after pushing their bodies this hard, but Haruto found a way to use his own exhaustion to his advantage. Instead of resting, he treated himself after intense workouts and sparring sessions. His theory was that his body, already primed for recovery after a hard day of training, would respond even better to the medical treatments. He was pushing his cells to work overtime, speeding up their healing and maximizing the benefits of his treatments.
The results were not immediate, and every session left him sore and aching. But each time, he could feel subtle changes—slightly stronger muscles, a little more resilience in his bones. The seals released precise bursts of medical chakra, and while the process hurt, it was bearable. Haruto's goals were clear, and no amount of discomfort was going to slow him down.
There were side effects, though. He deducted that the treatments would caus his body temperature to spike. His cells, working overtime to grow and repair, generated more heat than he could manage on his own. Haruto found that ice baths became essential. After each session, he would sit in freezing water, allowing the cold to reduce the inflammation in his muscles and cool down his overheated body. It wasn't pleasant, but it was necessary.
This transformation wouldn't happen overnight. It would take years of consistent effort. But Haruto had planned for this. His research, his calculations, and his experiments all pointed to this being the right course of action. He was patient, methodical, and driven. He knew he had a limited window—the years of puberty, when his body would be naturally growing and adapting—and he had to make the most of it.
The real question was: Could he handle the pain? Haruto knew this path would be physically and mentally grueling, but he had already made up his mind. Pain, like everything else, was an obstacle to be overcome. If this was the price for his future strength, he was more than willing to pay it.
The only thing left was funding. The seals, the medical equipment, the ice baths—everything cost ryo, and Haruto realized that nearly all the money he earned from missions would have to go toward this endeavor. He didn't mind. The apartment he lived in was small and modest, and Haruto saw no need to move out for the foreseeable future. He could focus all his resources on his body's enhancement, understanding that this was an investment in his future.
Haruto imagined looking like a mummy when he went into the ice baths in the future.
There were still countless unknowns ahead, but Haruto was committed to seeing this project through, no matter the cost. He would reshape himself into the shinobi he envisioned, one painstaking step at a time.