(I have made a few modifications at the last of the Chapter, removing that part from this chapter and writing it in the next one.)
"Now, we will begin our training." Guy and Sakura could be seen in the training ground early in the morning.
"Wait a minute. Let me rest for a while." Sakura said, breathing heavily.
Guy has come to pick her up early in the morning. Then she had to run from her house to the training ground, chasing after the Guy. If she tried to keep up with Guy, he would increase his speed, but if she slowed down, he wouldn't decrease his speed. So, she ran at full speed for 10 minutes or so.
Without the enhancement brought by the athletic body and anger clouding her mind, she wouldn't have been able to reach here this fast. Now that her anger has gone down, her legs are starting to hurt.
"Sakura, training and rest cannot exist in the same place. When we rest, there will be no training, and when we train, there is no room for rest." Guy said like those old martial arts masters teaching their pupils. On second thought, he is a martial arts master teaching his pupil.
"I don't know anything about Ninjustus, taijutsu, Genjutsu, even chakra, and so on. Why don't you start from there? I will listen while resting." Sakura used her clever mind.
"I forgot you don't know anything about ninjas." Guy then began to think about what to say.
"Ok, then let's start with chakra. In this world, every living being has a chakra, whether it is a plant, animal, or human. Most of them cannot use it because they have very little or don't know how. It is said that the Sage of the Six Paths is the source of all chakra, and that he spread it across the world and taught humans how to use it."
"We ninja use chakra for ninjutsu, genjutsu, and taijutsu. Yes, even taijutsu uses chakra." Guy then lifted his foot and stomped on the ground, compressing the soil and leaving a foot-shaped hole.
"That's it? What is he trying to show?" She felt it was anticlimactic. "Isn't he trying to show chakra enhancement?"
"I wasn't using chakra now. Look at the damage I did to the ground; it is minimal, but if I had kicked an enemy with similar force, his bones would have broken. Ground is good at absorbing force." Guy raised his feet again, but this time, Sakura could see a bluish, water-like substance coating Guy's feet.
"Isn't chakra supposed to be invisible, only becoming visible when someone has too much of it? Is he using a large amount just to show me that chakra is used in taijutsu?" Sakura wondered.
This time, cracks began to appear in the ground after Guy stomped. They radiated from Guy reaching up to Sakura.
"He can also use chakra enhancement like Tsunade, causing massive damage." Sakura stared in shock. "Of course he can. He's a taijutsu expert, though the radius of impact isn't as large as Tsunade's or Sakura's."
She had seen it in anime before, but witnessing it in person was a completely different experience. The ground was cracked as if from an earthquake..
"I used chakra this time to spread the damage. It needs a huge amount of chakra and good chakra control to do so. Mine is smaller than in comparison to Tsunade-sama, who can cause even larger destruction." Guy said being humble.
"That's why his damage radius was smaller because his chakra control isn't as good as Tsunade and Sakura. But the chakra can't be controlled outside the body, right? Then how did they spread it so far and cause damage?" She felt there was a secret to Tsunade's method of chakra enhancement, and Guy seemed to figure out something similar.
"Look again, this time I'll focus it on one spot." Guy stomped again, but this time the ground around him rose slightly while the spot where he struck sank, leaving a foot-shaped hole in the center.
"Come and look at the hole I made," Guy called to Sakura. Sakura also curiously went near the hole and looked.
"What? It's so deep." She was shocked. The hole looked like it was made to insert a pole in the ground, if its shape is ignored.
"This time, I focused the chakra on the point of impact and only allowed it to go straight down. So, chakra is used in taijutsu to control, spread, or increase the damage. This is done through chakra enhancement. Now, let me show you another part of this. For this, I need a stone." Guy looked around to find a stone.
"Found it," Guy picked a stone and handed it to Sakura. "Now, use the stone and hit me using the stone in my hand with your full strength." He said with his hand forward.
"What? Hit you in the hand?" Sakura asked in confusion.
"Don't worry. I'll use chakra enhancement to protect myself. This is something every Jonin knows," Guy assured her. He even made his chakra visible to show he was using it for defense.
"Ok, then." Sakura struck his hand with full strength. The stone didn't cause any damage; it felt like hitting something soft and water-like, but also hard. Mud-like might be a better word, or is it? She felt very strange.
"That felt weird," she said to Guy. "Like striking dough, soft yet hard at the same time." She'd finally found the right way to describe it.
"Sorry, I used too much chakra." Guy wasn't trying to show her this. He had used a huge amount of chakra to make it visible, but didn't know it would have this effect.
He finally knows why he sustains less external damage when he opens the higher gates of the eight gates technique. The excessive chakra that radiates from him protects him like how the chakra of tailed beasts protects their jinchuriki.
But no ninja wastes chakra like this. His chakra would deplete within a minute if he kept defending like this in a normal battle.
"It seems I have to learn to control the excessive chakra produced when opening the eight gates." Guy had an idea. He can't use most of the chakra produced when he opens the chakra gates, so the chakra radiates from his body to the surroundings.
"If I can control it and use it like a chakra cloak of a jinchuriki, I can minimize external damage even more." Now he had a new training goal, the hardest one he'd set so far.
"It will be very difficult to control the erratic chakra produced by the opened gates, but when have I ever backed down from training?" Guy was getting pumped up.
"Yosh, I have something new to master now. It may seem impossible, and may as well be impossible, but I will train to achieve it." Guy said it aloud.
"After I mastered the Eight Gates technique, I had fulfilled my ambition. From that day, I had nothing left to strive for. I was like a machine, repeating the same training routine without direction. But now that I have a new purpose, a new target, and a new training routine for it. The calm youthful energy is surging again." Guy said with tears of happiness in his eyes.
"He has lost it again, right?" Sakura asked herself after hearing Guy shout something out of the blue.
"Thank you, Sakura. You have given a new purpose to my life that had become dull after I mastered the eight gates technique." Guy said, thanking her.
"So, accepting me as a student hadn't brightened your dull life." Sakura's mouth twitched. "So, your student comes after winning against Kakashi and training in your priority. I finally know why you are and will be single. I don't know where your wife or girlfriend will be in your list."
*****
"Now, let me show you another way of using chakra," Guy said to Sakura. He walked over to the nearest tree and began walking up its trunk vertically, as casually as if it were flat ground.
"Wow." Sakura was genuinely surprised. It looked strange; her brain, still wired to the normal world of Earth and the civilian life of this one, reacted oddly to the sight. She couldn't help but also marvel at the core strength it must take to stand straight on a vertical surface. And this was something every genin could do; even Sakura did it. It means the ninja academy must have forced her to train, or she was like those 'Chinese beauties' who were as light as a feather.
It reminded her of those stunts on Earth where an athletic guy grips a vertical pole and balances horizontally, his body parallel to the ground. Many could do pull-ups, but very few could perform that trick because it required incredible core strength.
"You can use Chakra to climb trees and even walk on water. This is basic chakra control that every Chunin and many Genins know."
"Now, let me show the final use of Chakra in battle." Guy then took out a shuriken and threw it at the opposite tree. The shuriken hit the tree and got embedded in it.
"I wasn't using Chakra, so it completely penetrated the tree, but if I use Chakra-," a glowing Shruken appeared in Guy's hand, which he threw at the same tree. This time, completely passing through it.
"You can use chakra to strengthen or sharpen your weapon. So, it can be deadly, especially if you are fighting a wind release user. They can make their weapon very sharp with wind chakra." Guy warned Sakura as he returned to his earlier position.
"Sharpening of your ninja tools or weapons is an advanced form of Chakra control, and most of the ninja who use this are jonin. On the other hand, Jonins have quick reflexes, so this may not work on them. But the ninjas who use Wind chakra to sharpen their weapons are very dangerous in close combat." Guy told Sakura.
"This is all the way chakra can be used in Taijutsu. They are also used for Ninjutsu, Genjutsu, and Fuinjutsu. Like how oil is the fuel of an oil lamp, the chakra is the fuel of a ninja. Without the chakra, you are just a target on the battlefield. So, as a ninja, you must learn to conserve and use Chakra appropriately. Flashy ninjutsu will only deplete your chakra, so choose only those that are useful."
"This is all about Chakra for now. You will learn more about it as you get stronger." Guy said, concluding the topic of chakra.
"Did he forget about the chakra nature?" Sakura thought, "Should I remind him?"
"Then if he asks how I knew about this, then what will I say? I know about it, so that's enough."
"Now, we will start your training." Guy reminded Sakura, who was sitting on the ground like she was here to watch a show.
"Okay," She had rested enough when Guy told and showed the uses of Chakra, so Sakura was ready to start the training.