Disclaimer: First Chapter
Merry Christmas.
Story Start!

To think her mother went through such harsh training.

The First Step.

When Kuroka had been given a balloon of water and told to pop it using nothing but her chakra, she had been showed how to do it and allowed to figure the rest out for herself. With her fine chakra control, and her nature, she had been able to figure it out for the most part. She figured out that you have to inject a lot of mini-spirals into the balloon in order to make it pop the way that it had been showed. At the same time, making a single perfect spiral had taken her a good bit of effort that she had taken days of training for.

The First Step had taken Kuroka 5 weeks of non-stop training to accomplish, and according to Naruto she had taken far less time than her mother in that step.

The Second Step.

The Rubber Ball with no water in it, suffice to say, it was a lot harder to make something pop when it had liquid in it. Not to mention the thick walls of the rubber ball just didn't want to pop, they morphed to the shape of the chakra inside of it far too easily. This training needed chakra so intense that it was visible easily to the naked eye, and chakra dense enough to cause pain to the user, as well as damage them if they weren't trained to handle it. Her own hands were covered in dense chakra burns from where she overloaded her chakra into her hands, something apparently she was suffering worse from than her mother, who had far weaker chakra than she herself had.

*POP*

"Well done Kuroka, you've actually managed the Second Step... with this you've come farther than even your mother did." Naruto congratulated her for her achievement well done. She was only the second student to have ever come this far, though before her not a single student had ever actually managed to complete the Third Step of this training. Yokai just weren't in tune with using their chakra in this kind of way, so this training was far harsher on them than it was for those who were more used to using chakra in it's raw form.

Yokai almost never used raw chakra, they always... literally almost always, converted it into Youjutsu or some kind of elemental attack. It was never pure chakra alone, so for Kuroka to achieve the Second Step within 8 months of training was truly something he would call genius of her to manage.

The only other student to achieve the Second Step took 29 years to manage what she managed to do in 8 months.

"It hurts... a lot nyan." Kuroka's hands were bloody from what she had managed to do, her burns had reopened from popping the rubber ball, and they were bleeding freely. "So... how many more steps nya?" Kuroka asked Naruto, and he looked at her with a curious eye.

"Well, for the incomplete version only 1 more step. The Incomplete Version is powerful, and is ranked A in difficulty. The complete version has 4 more steps though, and is ranked at S in difficulty, the highest rank in my ranking system." Naruto explained to her. He was only expecting her, at most, to complete the Third Step before he went on to teaching her actual Senjutsu though, the reason that she came here.

When the Third Step was completed, usually, one's Physical and Spiritual energies were more harmonized and control over both of them would be far more natural. Being able to control Physical and Spiritual energy in equal amounts was something that Senjutsu users really needed to have mastered in order for them to balance them with Nature Energy, fuse it with their chakra, and form Senjutsu Chakra in perfect amounts.

For Yokai, Senjutsu came to them naturally.

They were not perfectly balanced though, so they succumbed far more easily to the negatives of Senjutsu. While in this world, you didn't turn into an animal or turn into stone, the world still punished you for not mastering or balancing Senjutsu, by causing you to lose control of yourself and become drunk on power.

"4 more steps!?"

"If you want to undergo that level of training, sure, 4 more steps. That level of training isn't needed to start you on Senjutsu though. As you are right now, I would say you've become balanced enough to start Senjutsu training... but completing the Third Step would really be best." Naruto admitted her readiness. If she didn't want to complete the Third Step, and go right onto Senjutsu, then he would start her training in that once she had recovered herself enough that she could be healthier when she started.

Learning the Rasengan opened an entire new world of attack possibilities, it was a supreme technique that could be blended perfectly with any style of combat. It had offensive and defensive abilities, support abilities, and it was only limited by the creativity of the user itself. For any Senjutsu user, the Rasengan was a dream come true with how versatile it was in all of it's uses.

He even used it for cooking on occassion.

"... I'll do the Third Step..." Kuroka looked him right in the eyes.

Naruto tossed her a balloon.

It was a simple balloon, not a rubber one, it was the water balloon but without any water in it at all.

Kuroka popped it.

"... Don't pop it. Combine the First and Second Step together, use all of the power of the Second Step, but combine it with the fine control of the First Step. If you manage to master the Third Step, this is what your goal should be." Naruto held up another balloon, figuring the hot headed student would pop it right away. He showed her the balloon, before he showed her his other hand.

A yellow sphere of chakra appeared in it.

It was beautiful, Kuroka could see an uncountable number of super condensed spirals inside of the sphere. The sphere was absolutely perfectly round, and she looked at the balloon and she could sense chakra inside of it. Yes the surface of the balloon never once moved or made any bumps at all, showing the absolute control of chakra required to control so many precise spirals inside of it to a single, controlled ball.

"It's... it is like you are... controlling something uncontrollable... This technique is contradiction itself." Kuroka was seeing two extremely opposite forms of chakra control being used together. Uncontrollable power, and extremely fine control, being fused together. This technique was worthy of being called A-rank in difficulty of learning, by Naruto's standards. The very act of using this technique required you to maintain and create both wild spirals, and control those wild spirals into a perfectly controlled shape.

To manage this was something that should be impossible.

It was forcing your body to create and maintain contradicting forces within itself, project it outside of itself, while maintaining control of it as if it was still inside of itself as well. Seeing the end goal of the First Three Steps, Kuroka could feel just how far one would need to come in chakra control in order to master this step alone.

"Even where I came from, only a handful of people knew this technique. My father created it, and it took him 3 years. He taught his Master and his Student, my Master taught it to me, and I taught it to my Disciple... who taught it to my Son. This technique isn't just a technique, this technique represents a bond... this is the bond between Father and Son, Master and Apprentice... if you learn this technique, you will truly become my Apprentice." Naruto stated to her with a soft smile as he looked at the technique, the entire history of it.

He had many students.

The only person he had taught this technique to, who had actually learned it, was his own Disciple Konohamaru, who became a famed Jonin who served him faithfully while he had been Hokage. The man he had trusted to look after his own child, his rival's child, and the child of a villain, and teach the trio of them.

Those who mastered the Rasengan were destined for great things.

Minato Namikaze, creator of the Rasengan, went on to become the Fourth Hokage and became feared by entire nations. A man who could slay entire armies in a blink of an eye, in a flash of yellow, and a skilled user of Senjutsu.

Jiraiya, Toad Sage of the Sannin, who was feared as a ninja who it would take an army to defeat, a powerful Senjutsu user (though not a master). A man who had been considered for the role Fifth Hokage, and man with a successful spy network that went through the entire Elemental Nations.

Kakashi Hatake, a man who was feared in the Bingo Books, a ninja who was greatly respected by the nations and famously cut lightning itself in half, and copied over a 1,000 techniques. A man who had become the Sixth Hokage, even without his Sharingan eye to aid him. A highly skilled and feared ninja in his own right.

Naruto Uzumaki, the most powerful ninja in history, who created world peace and saved the villages countless times, and even the world many times. Only 1 other Shinobi in history could rival his fighting ability, his only rival, and if he fought every single ninja in the world by himself, he would win hands down. A ninja who had become the Seventh Hokage, and lead the entire world into an era of peace and prosperity.

Konohamaru Sarutobi, a powerful and elite shinobi of the Sarutobi clan, one of the strongest ninja of the Hidden Leaf Village, a ninja who had the potential to one day be the next Hokage of the time when Naruto handed down the title. One of the very few ninja capable of handling the title.

Boruto Uzumaki, a Genin with the strength and skill to rival even Jonin-level ninja, a natural genius, and had assisted in the death of an Otsutsuki by dealing the final blow. His potential had been great, with skills far surpassing the average ninja even at a young age.

"A bond... a technique can be a bond nyan?" Kuroka looked at the technique.

It had such a powerful weight to it.

It was more than just a technique.

"Yes, this technique isn't just an attack, it's a bond that is forged between Master and Apprentice. All those who have learned this technique have the potential for greatness, because they carry with them the will of their Master and the Masters before them. The weight behind this technique is immense, and if you Master it, that weight will fall onto your shoulders next." Naruto's Rasengan started to grow.

It became the size of a basketball.

It became the size of a car.

Kuroka watched as he held the growing technique above his head, as the light grew more intense to the point it was harder to look at the growing sphere. The immense power inside of it was so great and dense though that she felt her skin tingling. Her jaw dropped when the technique continued to grow in size until it was even larger than Naruto's house, and he smiled down at her.

"That... it's impossible... I can't even sense how much power that is."

"This is the power that could destroy this planet. Right now, I'm holding above my head an attack with enough power to blow this planet to pieces. This isn't even the full power of this technique, the Rasengan is a technique that has no limits... and that infinite potential is the weight that those who learn this technique have to carry with them." Naruto told her as he shrunk the Rasengan down as he allowed the technique to very safely shrink down to a manageable size.

That was equal to the size of the Rasengan that he had created for his son Boruto to wield when he dealt the finishing blow against Momoshiki. A technique that had next to an unknown planet, in an unknown universe, with an explosion so large that it was larger than a moon. An explosion so large it would have wiped out an entire planet if it hit. Of course, he had wielded power even greater than the power he was showing Kuroka for a long, long time, since he was about her age.

He just never had a chance to use 100% of any attack he had... ever, considering if he ever used a 100% attack it would spell... well doom for wherever he was.

"That's... heavy... it's really heavy nya." Kuroka was both awed and shocked by the very fact that she had been standing in front of something so amazing. She had just witnessed a power greater than anything she could imagine, greater than even the Dragon God, or the Top 10 were capable of. It was a technique that was not only immensely strong, but had such a heavy history behind it that it was hard to quantify just how large it was. "... You... you teach this technique... to..."

"Nobody has mastered this technique, of all of the students who came to this island, not a single person has ever managed to master it and become my True Apprentice. I've had many students, but since being stuck on this world, I've tried to teach this technique to all who come here, so I can find myself a student who will become my Apprentice... a person I can truly pass down all my teachings to." Naruto ended the Rasengan, and he held his hand down to Kuroka.

She blinked.

She was sitting down... but she didn't remember sitting, she had been standing. When had she collapsed on her butt, was she that floored by the weight of the Rasengan that she just couldn't stand in the presence of it?

"Can... can I really... am I worthy?"

Naruto smiled at her.

"If you learn the Rasengan, then you will have to prove your worthy of it. As my student, I'll beat into your head everything you need to become worthy of handling this weight." Naruto told Kuroka with gentle eyes.

She took his hand.

Chapter End!
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