Today, Senju Tobirama spoke about knowledge regarding Ninjutsu. The Ninjutsu used by Ninjas are diverse; if one removes some special Ninjutsu, what remains are the Doton based on seven attributes, and these Doton are basically what Ninjas use for combat.
The foundation for Ninjas to use Ninjutsu is hand seals. Only by forming the corresponding hand seals can the Ninjutsu be released. This is because a Ninja's hand seals have the function of guiding Chakra. It is said that they were developed by the progenitor of Ninjutsu, the Six Paths Sage, and there are twelve in total.
Each hand seal corresponds to a specific flow of Chakra. The more complex the Ninjutsu, the more hand seals are required, and the more frequent the circulation of Chakra within the body. Only in this way can powerful Ninjutsu be released.
As far as Fūmori Masaki knows, the composition of Ninjutsu consists of two changes in Chakra. The first is Nature Transformation, which is the foundation of all Doton; without Nature Transformation, one cannot use the corresponding Doton. The second is Shape Transformation; by changing the shape of the Chakra, the power is increased.
Generally speaking, the higher the degree of Nature Transformation and the more perfect the degree of Shape Transformation, the greater the power of the Doton. All Doton follow this rule.
However, although Ninja clans know that the power of Doton is determined by these two factors, they each have their own theories on how to improve these two changes.
At this time, there were no specific training methods for Doton. The scrolls passed down by the clans only recorded some hand seals and the experience and insights of the developers.
When Ninjas from clans practiced Ninjutsu, they would practice hand seals to induce the self-circulation of Chakra, and subsequently learn the Doton. The result was a heavy reliance on the learner's talent.
The flow of Chakra guided by hand seals is limited. Those with outstanding talent can comprehend Chakra Nature Transformation from the circulation of Chakra, while those with poor talent struggle to grasp it in a short time and must practice continuously to have a chance of learning it. As for how to improve the nature of Chakra, that is an even greater challenge.
But now, Senju Tobirama is telling everyone a method to master Chakra Nature Transformation without needing to practice hand seals.
The reason why it was necessary to practice Nature Transformation through hand seals in the past was that Ninja clans did not know how to conduct Nature Transformation. Only through the guidance of hand seals could one grasp the feeling of that Nature Transformation and thus learn it.
Due to war and issues with the inheritance of Secret Techniques, Ninja clans did not have time to study the underlying reasons for Nature Transformation, which led to this tradition. Naturally, Senju Tobirama could not sit by and watch this situation continue. Possessing a spirit of research, he carefully studied every scroll and, combined with his own insights into Ninjutsu, finally understood the secret of Nature Transformation.
"Simply put, it is to make Chakra exhibit the corresponding nature," Senju Tobirama said. "Although the Doton we use look like real, tangible substances, the real reason is just that they attract external substances or mimic them, while the power is still provided by Chakra."
"Although we divide Chakra into Fire, Water, Wind, Earth, and Lightning, I can now tell you that the true meaning of Chakra nature is not the literal meaning, but one in another sense," Senju Tobirama said, then brought out a bowl of water. "For example, when using Water Release, what we need to do is not to turn Chakra into water—that is just on the surface and meaningless—but to make Chakra exhibit the nature of water, just like this."
Senju Tobirama placed his finger into the water and immediately injected his Chakra. In the eyes of everyone, the water in the bowl suddenly began to swirl rapidly, splashing, and forming a small whirlpool.
For a moment, sounds of surprise rang out in the classroom. In the past, they had always relied on Doton to use Nature Transformation; they had never used Nature Transformation purely with Chakra before. This move by Senju Tobirama truly shocked them.
"That is roughly how it works," Senju Tobirama removed his finger from the bowl, and the swirling vortex of water slowly calmed down. He then said to everyone, "The surface of the Doton we use is just like Transformation Jutsu, utilizing the disguise of Chakra. What truly gives them power is still Chakra. And what I just used was to make Chakra exhibit the characteristic of flow. Flowing Chakra itself carries power, and it is precisely because of this that it can endow Chakra with an impact force like water."
"Lord Tobirama, if that is the case, is it the same reason for other Doton? Then, why can Fire Release ignite trees or burn others?" Hiruzen Sarutobi asked hurriedly.
Senju Tobirama did not answer directly but asked in return, "Hiruzen, why do you think fire can ignite trees?"
"This..." Hiruzen Sarutobi was stunned and lowered his head to think hard.
"How about I ask a different question? Generally, when you do not have a source of fire, what method do you use to start a fire?" Senju Tobirama said.
"Uh, Fire Release... No, no, no!" Hiruzen Sarutobi replied subconsciously, but after seeing Senju Tobirama's gaze, he shook his head quickly. "I heard that nobles use a type of stone that can strike sparks, and then after touching it with something flammable, they can ignite a flame."
Senju Tobirama said, "This answer is not wrong, but what I want to ask is not this, but the essence of it. It is said that people in the past would use the method of drilling wood to make fire, drilling wood to produce sparks, and thereby start a fire. So, what is the reason that brings out the sparks?"
"It is heat." At this moment, a voice spoke. Senju Tobirama raised his head and cast his gaze over, discovering that the speaker was Fūmori Masaki.
Fūmori Masaki looked at Senju Tobirama and said, "It is heat. Extremely high heat will cause combustion. Lord Tobirama, I believe that is the reason."
Senju Tobirama looked deeply at Fūmori Masaki and then said to the others, "I share the same view as Fūmori. The reason why fire can ignite items is because of heat. Regarding Fire Release, isn't our intuitive feeling that it is very hot and scalding?"
"Indeed." Hiruzen Sarutobi thought for a moment and said.
At this time, Senju Tobirama asked Fūmori Masaki, "Then Fūmori, what do you think the Chakra nature of Wind Release should be like?"
Fūmori Masaki naturally knew. The first Chakra nature he knew was Wind Release—learned from that comic book—so he replied, "Lord Tobirama, I think the Chakra nature of Wind Release is cutting."
Senju Tobirama suddenly chuckled, and the others immediately looked at him in surprise. You must know, Senju Tobirama had always presented himself with a serious image, and no one had ever seen him smile before.
"Well said, Fūmori." Senju Tobirama applauded. "I did not expect you to be able to give such a great answer. My opinion of you has changed."
The others looked at Fūmori Masaki; some had looks of surprise, some had looks of confusion, and some had looks of jealousy. Their impression of Fūmori Masaki was still stuck in the past. The current Fūmori Masaki truly exceeded their imagination, and this guy had even received praise from Senju Tobirama. Everyone knew that being able to leave a good impression on Senju Tobirama meant being one step closer to becoming his disciple.
Fūmori Masaki let out a soft breath at this moment. He knew Senju Tobirama's personality, which is why he spoke up to show himself off. Although he had the aptitude for Sage Arts, it was highly likely he would be taken as a disciple. But becoming a disciple was not his ultimate goal; his true goal was to become the successor to the Hokage. To that end, Fūmori Masaki had to demonstrate other qualities, and this answer undoubtedly aligned with Senju Tobirama's wishes.
"You are really amazing, Masaki-kun." Uchiha Kagami whispered to Fūmori Masaki.
Hearing this, Fūmori Masaki smiled faintly, "It's alright."
At this time, Senju Tobirama said to everyone present, "I will stop here. Everyone can try to practice their own or other Chakra natures. I believe that as long as you follow this direction, the threshold for learning Chakra nature will be lowered. But I will say one thing in advance: whether it is flow, heat, or cutting, these are just my own and Fūmori's ideas. You do not have to follow this path; you can look for other directions, and perhaps you will have your own gains. If there is anything you need to ask, you can also come to me for advice."
Senju Tobirama took everyone to the practice field. The practice field inside Konoha Academy was very large and could fully accommodate thirty-eight students. After everyone arrived at the practice field, they excitedly went to try the method Senju Tobirama spoke of. They first wanted to test the Ninjutsu they knew. If what Senju Tobirama said was true and could reduce the difficulty of learning Nature Transformation, then they could try to develop other Chakra attributes—in the past, this was a privilege that belonged only to geniuses.
Fūmori Masaki was also prepared to verify it—although he already knew from the comic book that Wind Release Chakra was indeed like this—and Uchiha Kagami hurried over at this time, smiling, "Masaki-kun, don't forget what we agreed upon, that we would practice together."
"Yes." Fūmori Masaki nodded and smiled, "Then let's do it together, Kagami-kun."