Hashirama Senju's gaze was firm as he said with conviction, "Madara won't hurt Konoha. He won't even appear in Konoha again. Our final battle was his last farewell to me and the village. If there's anything in Konoha that Madara still cares about, it's Tobirama alone. Tobirama killed Madara's most beloved younger brother and used schemes to force the Uchiha Clan to break with him. So if Tobirama gives Madara a chance to kill him, Madara will definitely take it. But if Tobirama wants to escape, no one in this world can kill him. And without absolute certainty, Madara definitely won't act against Tobirama rashly."
Listening to him, Tsubasa couldn't help saying, "I really envy the bond between you and Lord Madara. It's just that fate played a cruel trick on you, and in the end, it didn't have a perfect ending."
Hashirama laughed heartily. "I'm telling you this mainly because you're my only personal disciple, and you should know about my past. Our generation brought an end to the chaos of the Warring States period, and as my successor, you naturally inherit my mission as well."
Tsubasa smiled wryly and asked, "What exactly is that mission?"
Smiling, Hashirama gave him his charge. "After I die, you'll officially become the head of the Senju Clan. Listen carefully to your master's wife and your martial uncle Tobirama in all matters. You must lead the Senju Clan down a path to true peace."
Tsubasa's mouth fell open in an "O" of surprise. This was too much-he had become the clan's successor on his first day as a disciple.
Seeing his reaction, Hashirama burst out laughing again. "Don't worry. Tobirama is only forty now, so he can assist you for at least another thirty years or so. By then, you should be able to stand on your own. With your intelligence, Konoha as Tobirama has built it, and the powerful Senju Clan backing you, I don't think it will be difficult for you to bring peace to the Shinobi World. For now, you only need to do two things: do everything you can to become stronger, and learn how to manage the clan."
Tsubasa groaned inwardly. He was a transmigrator, after all, and knew full well that Tobirama didn't have long to live after Hashirama's death. When the time came, how could the Senju Clan ever accept a child barely in his teens? But he absolutely couldn't reveal that he was a transmigrator. It would be a disaster if Tobirama Senju dragged him off and sliced him up for research. Tobirama was ruthless enough to slice up even his own elder brother for research after his death. For now, Tsubasa would devote himself to training and be a happy young man.
With that thought, Tsubasa responded solemnly to Hashirama. "I won't disappoint you, Master. I'll do everything I can to improve my strength and usher in an era of true peace and prosperity."
"All right, I've told you all this to say that no matter what your goals in life are, while you're pursuing them, you should also help your master fulfill this wish. And as for what we owe Madara, you need to know how to handle it if you meet him someday."
Looking into Hashirama's sincere eyes, Tsubasa replied just as sincerely, "Master, I have a goal in life of my own now. I want to live forever."
Hashirama Senju was dumbfounded. What kind of ambition was living forever? He smiled helplessly and asked, "Who could possibly live forever?"
Tsubasa asked in return, "Why not? The sages of the Three Great Sage Lands are said to have lived for thousands of years, so why can't we humans do the same?"
Hashirama smiled. "Then work hard to become an immortal sage, Little Tsubasa. Just don't forget to help your master fulfill his wish along the way."
Tsubasa replied, "I understand. I'll lead the Senju Clan in bringing true peace to the Shinobi World, and if I meet Lord Madara, I'll apologize to him for you and repay him a favor while I'm at it."
Hashirama nodded with a smile. "That's about it. All right, back to the matter at hand. What I'm going to teach you today is the Senju Clan's exclusive Chakra Extraction Technique. Chakra is the product of combining spiritual energy and physical energy. A complete person can be viewed in two aspects: the body represents Yang Release, and the soul represents Yin Release. The quality, strength, or talent a person possesses in these two aspects determines that person's lower limit."
Tsubasa asked curiously, "Then what determines a person's upper limit?"
Hashirama Senju laughed heartily. "In theory, no one has an upper limit. In other words, everyone has a chance to become a God of Shinobi like me, or even surpass me. Many factors affect a person's upper limit: cultivation methods, secret techniques, temperament, willpower, heavenly materials and earthly treasures, and comprehension can all raise it. There are even some utterly inhumane methods, such as genetic modification, genetic mutation, and genetic evolution. So when we select ninja, we only look at their lower limits."
Tsubasa asked again, "Then how do you find out a person's lower limit? How do you judge it?"
Hashirama explained patiently, "There are many ways to find out a person's lower limit. For example, we set an ordinary person's physical and spiritual values at one hundred. The Ninja Academy uses various physical test results to determine a person's Yang Release lower limit. The Yin Release lower limit is determined by how long it takes for the person's soul to successfully communicate with the body. The criterion for admission to the Ninja Academy is to pass these two tests: anyone whose values are higher than an ordinary person's one hundred passes, while those below the standard are eliminated. Of course, that doesn't mean those who are eliminated can't become ninja later. They might have fortuitous encounters or become ninja through hard work afterward. The academy's resources are limited, so we have to select the best of the best and give the best resources to those with talent."
"Oh, I understand. But what does that have to do with the Chakra Extraction Technique?"
Hashirama continued, "Because the amounts of Yin and Yang Release differ from person to person, the proportions of Yin and Yang in a Chakra Extraction Technique can't be the same either. This determines the grade of the Chakra Extraction Technique. For example, we Senju place greater emphasis on physique, so we need to increase the Yang Release proportion and reduce the Yin Release proportion. The Uchiha Clan is just the opposite. The amount of Yin Release a person has also determines how much chakra they have and which nature it favors."
Seeing Tsubasa's bewildered expression, Hashirama gave another example. "Let's say your Yang Release is one thousand and your Yin Release is one hundred. In the first case, you combine one hundred Yang Release with one hundred Yin Release and extract two hundred units of chakra. That means nine hundred of your Yang Release is wasted, and you might never get beyond Genin in your entire life, because casting two C-rank Ninjutsu would nearly drain your chakra. In the second case, you combine ten units of Yang Release Chakra with one hundred units of Yin Release Chakra and ultimately extract eleven units of chakra. Then you could only be a prospective Genin. In the third case, you combine one hundred Yin Release Chakra with one thousand Yang Release Chakra and ultimately extract eleven hundred units of chakra, allowing you to become a Chunin. Combining them in different proportions produces different amounts of chakra. The amounts of Yin and Yang Release a person has determine how much chakra they can extract, while the different proportions used to combine them determine the maximum extent to which they can use their own Yin and Yang Release. Once a person settles on a chakra ratio of their own, they have to use that ratio to extract chakra from then on. Otherwise, the chakra will conflict and be incompatible, harming the body. Of course, some people use sinister secret techniques to modify themselves, forcibly absorb other people's chakra, and increase their own Yin and Yang Release to reach a higher level. But that harms both body and soul. Though they may gain power, they can no longer be considered normal humans, so those methods are all regarded as evil and unorthodox, and not worth pursuing."
Tsubasa nodded to show he understood.
Hashirama continued, "The ratios I just described are part of the Basic Chakra Extraction Method. It's a low-grade cultivation method and the one currently taught at the Ninja Academy. The academy requires everyone to work out their own chakra extraction ratio based on their individual proportions."
Tsubasa looked lost. "I thought the methods you just described were the high-, mid-, and low-grade extraction methods."
Hashirama smiled. "It seems your parents never told you about chakra cultivation! Most of those who don't extract chakra according to a ratio are wandering ninja. Major ninja villages like ours generally determine an extraction ratio based on each person's Yin and Yang Release, so they can extract as much chakra as possible. All right, now let's talk about the Mid-Grade Chakra Extraction Technique."