(Edited)
The results were clear, Tobirama's research had proven successful. When the heirs of the ninja clans practiced chakra transformation from a different perspective, they were pleasantly surprised to find that they had a deeper understanding of chakra's nature. Ninjutsu that had once been difficult to perform now became much easier to handle.
Previously, ninjas used special test papers made from trees that absorbed chakra properties to determine which chakra nature they were most suited to. From there, they would learn ninjutsu based on that chakra nature. Mastering additional chakra natures was generally reserved for the most talented individuals. Sarutobi Hiruzen's father, for example, had mastered multiple chakra natures, relying on his exceptional talent to do so.
However, the emergence of Tobirama's new method for practicing chakra nature transformation represented a major shift. The barrier to learning ninjutsu was effectively lowered. No longer did students have to rely solely on the guidance of existing ninjutsu to learn nature transformation. Instead, they could understand chakra attributes through their own practice, making the process more accessible to a wider range of students.
The first to try this new method was Sarutobi Hiruzen. After carefully considering Tobirama's teachings on chakra nature, Hiruzen decided to follow his suggestions fully. Without relying on any pre-existing ninjutsu, he practiced and eventually mastered a new chakra nature through his own efforts. Hiruzen's success inspired others, who became eager to explore other chakra natures themselves.
Fumori Masaki, however, did not rush. He was well aware of his limitations. While his potential was not extraordinary, his determination had earned him a spot as a student. He understood that even though Tobirama's method made learning chakra nature transformation easier, the fundamental limits of one's aptitude still applied. Only someone like Sarutobi Hiruzen might master all five chakra natures.
Masaki decided to focus on refining his wind chakra nature, his natural affinity. No ninjutsu would come more naturally to him than Wind Release. His understanding of Wind Release, informed by insights from another world, surpassed the common knowledge of the current ninja world, and his mastery of wind chakra had already advanced far beyond what it had been.
Masaki didn't avoid learning other elemental techniques, but with the looming threat of the First Ninja War, he knew that mastering a single chakra nature would be more practical. It could take ordinary people several years, even a decade, to fully master one chakra nature. Masaki believed that before the first war began, his best chance at survival and making an impact would be to completely master his wind chakra. Dividing his attention to learn multiple chakra natures would only weaken his abilities in battle.
Moreover, he knew that Konoha's first major enemy would be the Land of Lightning. The shinobi from Kumogakure specialized in Lightning Release, and his wind chakra was the natural counter to lightning.
Masaki resolved to fully master wind chakra, ensuring that he would be prepared when facing Kumogakure's forces. He wanted to increase his chances of survival and success in the upcoming war.
Tobirama observed the enthusiasm of the students with satisfaction, but he also knew that his method was still incomplete. Those who rushed to develop new chakra natures were making a fundamental mistake—they were neglecting their natural affinities in favor of diversifying their skills. In Tobirama's eyes, such behavior was misguided, as not everyone had the exceptional talent of Sarutobi Hiruzen. Those students were quietly removed from Tobirama's list of potential disciples.
For those who remained on his list, Tobirama maintained high standards. While their insight into chakra nature was a positive sign, it alone was not enough to qualify them as disciples. Over the next several months, Tobirama rigorously trained the students, subjecting them to increasingly difficult tests.
The training was grueling, and as time passed, the gap between students became evident. The exceptional students continued to excel, while others struggled to keep up. As the six-month mark approached, everyone knew that the time was near for Hashirama and Tobirama to choose their disciples from among the 38 students.
If there was one unexpected candidate, it was Fumori Masaki. The Fumori clan had been in decline for years, and Masaki was its last remaining member. He was not known for his natural talent, but rather for his relentless hard work in trying to revive his clan. Yet, despite these challenges, Masaki's performance in Tobirama's tests—whether in physical combat, technique, or ninjutsu—was on par with that of Sarutobi Hiruzen, surprising everyone.
Only Masaki himself and the Senju brothers knew the secret behind his rapid progress, Sage Arts. While some might consider this an unfair advantage, Tobirama and Hashirama saw it differently. The Sage Arts were a product of Masaki's own abilities, no different from any other powerful ninjutsu. His achievements were a testament to his own strength.
One day, after a particularly grueling session, Tobirama left the academy and headed towards the Hokage Tower. He felt that the time had come for him and his brother to officially announce their decision to take on disciples. As the future leaders of Konoha, it was essential to begin their training as early as possible.
The trial at Konoha Academy had been a success. The ninja heirs had studied together, forming bonds and pushing each other to improve. Tobirama and Hashirama had their list of potential disciples in mind, ready to help shape Konoha's future. Additionally, the trial had given Tobirama insight into a new approach to ninja warfare, inspired by the students.
During one of the tests, the heir of the Yamanaka clan had failed in a solo competition, losing badly. Teased by his friends, he explained that his family's secret techniques were not suited for single combat, and he felt it was unfair to be judged on those terms. This incident sparked an idea in Tobirama. The Yamanaka clan's techniques, indeed, were not designed for solo combat. They were most effective when combined with the abilities of the Nara and Akimichi clans—a formation known as the Ino-Shika-Cho trio.
The Ino-Shika-Cho combination had been renowned during the Warring States period for its complementary secret techniques, which, when used together, were far more powerful than any individual effort. Tobirama realized that this trio formation could be a model for future ninja teams, potentially offering unexpected advantages in battle.
Arriving at Hashirama's office, Tobirama knocked lightly on the door. Hashirama's response sounded weaker than usual, which Tobirama immediately noticed. When he entered, he found Hashirama sitting listlessly at his desk, one hand propped against his cheek as he stared blankly at a scroll. It was clear that his brother's mind was elsewhere.
"Nii-san," Tobirama said quietly.
"Huh? Oh, Tobirama, what is it?" Hashirama replied, forcing a smile.
Tobirama could tell something was wrong. Normally, Hashirama would have noticed who was at the door long before they entered.
"I wanted to discuss the academy with you," Tobirama began, carefully watching Hashirama's reaction.
Hashirama nodded absently. "Yes, it's time to choose our disciples. We should finalize the candidates."
"I've made my decisions," Tobirama said, listing the names of those he had selected.
Hashirama nodded in agreement as each name was mentioned. He had been keeping an eye on the academy as well and was satisfied with Tobirama's choices. When Tobirama mentioned Uchiha Kagami, however, Hashirama sighed.
"Uchiha Kagami... he is indeed very talented," Hashirama mused. "We should include him, Tobirama."
Tobirama frowned. "Nii-san, has something happened with the Uchiha clan?" He knew that for Hashirama to single out Kagami, there must be something going on with the Uchiha.
"Madara said something strange to me today," Hashirama admitted after a pause. "I'm feeling uneasy. I fear trouble might be on the horizon."
Tobirama shook his head in frustration. Even in these times of peace, Madara couldn't resist sowing discord. While Hashirama was deeply attached to his childhood bond with Madara, Tobirama had always been wary of him. Now, it seemed Tobirama's concerns were being validated.
"In any case, we should be prepared," Hashirama said with a weary smile. "Let's inform everyone that we'll soon be selecting our disciples from the academy. They should start getting ready."