Borrow Force, Return Force

After defeating Itachi, Yuun found that his standing within the clan seemed to have suddenly improved considerably. Even the Branch House members who gathered at the main gate every morning no longer looked at him with such disgust. Overall, though, Yuun's life had not changed much. He still attended classes every day and bickered with the little girl Hana Inuzuka, while Itachi sat quietly beside them, occasionally chiming in with a word or two. Several months passed like that.

"Why are you so happy today, Teacher?" Yuun asked Hizashi curiously. Hizashi was not exactly stern and humorless, but neither was he the type who smiled often. Yet today, a smile had remained on his face the entire time. He probably would not have been this happy even if he had become Hokage.

"Haha, Yuun, you're going to have a junior brother," Hizashi said with a smile. "I only found out this morning. It's already been three months."

"Really? Then congratulations, Teacher." Yuun hurriedly offered his congratulations. "You definitely have to treat us."

"Sure, sure. We won't eat at the clan compound tonight. Bring your mistress, and we'll all eat out together. It's on me," Hizashi said cheerfully.

"Hehe, I'm going to eat you bankrupt, Teacher." Yuun grinned. "Then how about we end early today?"

"Sure... not." Hizashi poked Yuun's forehead. "Don't even think about slacking off. Keep practicing properly."

"Urgh..." Yuun rubbed his forehead and assumed a stance. "Take this, Teacher—Gentle Fist!"

"That little strength isn't worth mentioning." Hizashi effortlessly blocked Yuun's attack, then casually countered with a palm strike.

"That's because you're playing dirty, Teacher." Yuun ducked beneath it and returned a palm strike.

"A ninja must endure what others cannot endure, so just endure it obediently." Hizashi laughed as he brushed aside Yuun's palm. "Today, I'll teach you a move: Eight Trigrams Vacuum Palm!"

A powerful blast of wind pressure rushed at him, forcing Yuun to close his eyes. By the time he opened them again, Hizashi had already withdrawn his hand and stood to the side, straightening his clothes.

"Teacher, how do you use that move?" Yuun's eyes gleamed, and he wished he could learn it immediately. With one swing of the palm, a gust of palm wind shot out. If he paired it with names like the Eighteen Dragon-Subduing Palms or the Palm of the Tathagata from his previous life, it would be the ultimate choice for looking cool.

"Hehe, even if I taught you now, you wouldn't be able to use it." Hizashi smiled as he explained, "Learning the Vacuum Palm is easy. It's simply releasing chakra to create wind pressure. The difficult part is outputting so much chakra at once, then compressing that wind pressure further to produce greater attack power. The chakra pathways of our clan are naturally thicker than those of ordinary ninja, which is why we can perform this technique. But at your age, it's still too early for you to use it. Your chakra pathways cannot bear the strain. When you're ready to learn it, I'll naturally teach you."

"What? I can't even learn it, yet you had the nerve to say you'd teach me a move." Yuun sounded dissatisfied.

"I'm sorry, all right? The moment you can learn it, I'll teach you first thing. I guarantee you'll master it." Hizashi smiled wryly.

"Teacher, I have a question." Having received the answer he wanted, Yuun nodded in satisfaction and raised another question. "When we use the Six... when we use Gentle Fist to attack enemies, why don't we just hold kunai and attack them directly? Instead of using our fingers to strike their acupoints and seal their chakra, wouldn't it be more worthwhile to poke a few holes in them with a kunai?"

"Someone actually raised that question a long time ago." Hizashi sighed. "At your current level, against the enemies you face, opening a few holes in them with a kunai would naturally defeat them easily. But what would you do against an enemy who can use Earth-style nature transformation? What would you do against an enemy wearing armor? Even if you never encountered such problems, once you got used to attacking with a kunai in hand, do you think you could still master a higher level of Gentle Fist?"

"Gentle Fist is a taijutsu with extremely weak destructive power, but it is also a taijutsu with extremely strong destructive power. Even a Tailed Beast has weaknesses. With the Byakugan's assistance, we can easily discover those weaknesses, then attack them by channeling chakra." Hizashi assumed a stance. "Our bloodline rejects all attribute ninjutsu. Chakra nature transformation has nothing to do with us either. What we can do, and what we need to do, is focus your chakra and strike it out! Eight Trigrams: Four-Sky Palm!"

With a single palm strike, a powerful blast of wind pressure, visible to the naked eye, howled forth. The condensed palm wind seemed so solid that one might mistake it for something tangible, smashing through several large trees in succession before finally dispersing.

"The Hyuga have their own pride. We remain a powerful ninja clan without those flashy, ornate ninjutsu! See through the enemy! Attack the enemy! Defeat the enemy! We are the strongest spear, and we are the strongest shield. So long as a pair of Byakugan still exists in this world, Gentle Fist will be passed down forever!"

After delivering those thunderous words, Hizashi left, leaving Yuun standing quietly alone on the training ground for a long time.

"Hyuga Yuun!" A loud shout pulled Yuun's attention back. The little girl Hana Inuzuka stood with her hands on her hips, glaring at him with wide eyes.

"What is it?" Yuun asked in confusion.

"You put your chopsticks into my lunchbox again!" Hana Inuzuka angrily picked up a large shrimp from Yuun's lunchbox and viciously stuffed it into her mouth. She mumbled, "This is compensation. You're not allowed to steal my food again."

"What's wrong with you?" Itachi glanced at Yuun. "You've been absent-minded all the time lately."

"Nothing." Yuun picked up a meatball and stuffed it into his mouth.

"Ah! You put your chopsticks into my lunchbox again..."

"..."

Yuun had a reason for frequently losing focus lately. The whole matter began with his last sparring session with Hizashi. During that fight, Hizashi's strength had knocked Yuun down several times. Yet according to Hizashi, he had not used strength greater than Yuun's at the time, and Hizashi had neither reason nor need to lie to him. If both sides had used the same amount of force, why had Hizashi sometimes been able to launch attacks Yuun could not withstand? The reason was simple: using four ounces to move a thousand pounds—Borrow Force, Return Force.

Although this kind of saying did not exist in the world of Naruto, the Hyuga Clan had unconsciously mastered this ability through their long-term practice and combat experience with Gentle Fist. However, without theoretical guidance or sufficient study of human biomechanics, Gentle Fist only displayed this characteristic under certain accidental circumstances. What Yuun needed to do was thoroughly grasp the principles and mechanisms behind this phenomenon, then make it his own.

After telling Hizashi about this phenomenon, master and disciple began researching it. Although Yuun knew nothing of its principles beyond those two phrases, with Hizashi—the ideal practitioner—there was no problem that could not be solved. Hizashi's rich combat experience and superb Gentle Fist, combined with Yuun's unconstrained imagination, allowed them to overcome one problem after another. What remained were only questions of human biomechanics.

For some reason, Hizashi refused Yuun's suggestion to involve other clan members. No matter how many times Yuun asked, he would not explain. If pressed too hard, he would merely pat Yuun's head and say that Yuun was too kind-hearted and would be too easily hurt in the future.

Without the clan's involvement, it was a pipe dream for Yuun and Hizashi, two outsiders who knew nothing about medicine, to research anything. Left with no choice, Yuun ran to bookstores and libraries whenever he had free time, hoping to find references in books. Hizashi, meanwhile, went to Konoha Hospital every day to seek help from his former teammates.