Chapter 1: Physical Skills Alone Won't Save the Ninja World

"Kid, believe in yourself. Even if you don't know ninjutsu, you can still become an amazing ninja!"

"Come on, let's keep pushing the limits. How about fifty circles of handstands if we don't finish?"

"…"

Kai gazed at the enthusiastic Guy and couldn't help but sigh inwardly.

He understood that Guy meant well.

However.

As a transmigrator, Kai knew the limits of focusing solely on physical skills.

Strong, yes, but only to a point.

The Eight Gates are impressive, right? But they're fleeting, like fireworks—brilliant yet short-lived. Kai didn't want to be a firework. Besides, being the same age as Lee, focusing solely on physical training would only get him to Lee's level.

What level is Lee at?

In the final battle, Lee opened the Sixth Gate. Apart from cheering and supporting, he couldn't do much more—watching his master fight desperately while he could only stand helplessly by. He believed that moment was incredibly despairing for Lee.

Kai didn't want to go through that.

So, he was well aware that focusing solely on physical skills had no future.

But he had no other choice.

Two years ago, he transmigrated into the Naruto world and discovered a glowing orb in his mind.

Then he found out he lacked the talent for nature transformation and genjutsu and couldn't even learn the simplest three-body technique.

However.

After some exploration, Kai found the benefits of the glowing orb.

First, his chakra control was exceptionally strong.

Second, he had a high talent for physical skills.

His control over his body and muscles was also very strong.

According to those teachers and Guy, many jōnin might not be as skilled in these aspects as he was.

As for the third…

He learned things very quickly.

He suspected all this was related to the mysterious orb, and over the past two years, he found that the orb seemed to grow stronger as he studied and researched.

So, he needed to come up with some ideas.

Sorry, Guy-sensei!

"Kai, you lack talent in ninjutsu and genjutsu. Are you going to give up on physical skills as well?"

Guy looked at Kai with disappointment.

He had taken Kai and Lee under his wing because they were both hardworking and didn't care about others' opinions. But after two years of perseverance, giving up now seemed like a lack of resolve.

"Guy-sensei, I'm not giving up. I'm just considering other options. Lee and I can't complete nature transformation, but we both have chakra, and I'm strong in control techniques. We can develop techniques that don't require nature transformation."

Kai continued running, breathing heavily as he shared his thoughts with Guy and Lee. "Even without hand signs or nature transformation, concentrating chakra can still have strong destructive power."

"But…"

"Like this."

Kai extended his right hand and concentrated chakra into a ball in his palm.

It wasn't the Rasengan but a concentrated chakra ball with destructive power.

Guy glanced at it, then his face showed surprise.

This is…

The Rasengan?

No, it's not the Rasengan. It's just a simple chakra aggregation ball.

"We often pass by the river while running. Recently, I thought, if I could make this concentrated chakra spin like a vortex, it would definitely have stronger destructive power."

Kai continued.

Exactly.

Since he transmigrated two years ago, he had been trying to replicate the Rasengan from the manga.

To make it practical, Kai didn't use the "balloon training method" from the manga but instead used similar principles and slowly mastered the technique over the past two years.

After speaking, he began to make the chakra spin.

The spinning chakra caused the ball inside to twist like a tornado, but the outer form remained perfect.

Guy was silent for a few seconds and then said, "Haven't you thought about adding more rotational directions?"

"Hm? Oh! How come I didn't think of that!"

Kai "came to his senses" and immediately tried it, but soon, the chakra ball dissipated.

He wasn't discouraged and prepared to try again.

However, Guy said with a heavy tone, "Kid, this technique you're working on is actually an A-rank technique called Rasengan."

"What? It already exists?"

Kai was "shocked" beyond belief.

"Yes, your technique is the same as the Fourth Hokage's Rasengan."

Guy nodded.

Lee, who had been silent, looked deeply shocked but seemed to understand the gravity of the situation.

"This…"

"Don't worry. Sometimes, it's normal for ideas and techniques to coincide. If your talent for nature transformation and genjutsu was better, you might have become an outstanding ninja."

Guy sighed.

Even without talent in ninjutsu, this kid didn't give up but instead came up with a new approach using untyped chakra. Such thinking and intelligence…

It's truly a pity.

"It's okay, Guy-sensei. The Sage of the Six Paths closed one door but opened a window. I should be grateful, and I believe that even without nature transformation, I can still become very strong!"

Kai's tone was firm.

At this moment, Lee, envious and excited, said, "Even though Kai-kun can't use ninjutsu, coming up with such a technique on his own is really amazing!"

"We need to learn physical skills and untyped ninjutsu and combine both."

Kai continued.

"That's called nin-taijutsu."

Guy reminded him.

After thinking for a moment, a smile appeared on Guy's face. "Let's go. Regardless, physical skills are still fundamental. Keep training!"

"Yes!"

The three continued their rigorous training, though each had their own thoughts, making the atmosphere somewhat subdued, even as they continued their hard work.

By evening, they each went their separate ways.

Kai returned to his assigned residence in the village, replaying the events of the day in his mind.

His thoughts were not just about nin-taijutsu, but as a commoner, the knowledge he could reasonably access was very limited.

If he mentioned brute strength, natural energy, or sage mode, it wouldn't attract attention but might bring scrutiny from the Anbu or Danzo, perhaps even a little "tea" from them.

"I'm sorry, Guy-sensei, but I really have no other options."

At twelve years old, with graduation coming in a few months and the Fourth Great Ninja War looming in a few years, time was running out!

Of course.

He didn't neglect ninjutsu training.

Back at home, Kai began refining chakra, shaping and concentrating it outside his body.

Currently, he could create chakra threads and use them to manipulate shuriken and kunai, but this wasn't the effect he wanted to achieve.

With his chakra nearly exhausted, he took out his notebook.

"Not strong enough, can't penetrate objects. Need to find ways to refine and concentrate it more."

"The strongest effect so far is still the Rasengan."

"I can't incorporate nature transformation, but there's still room for improvement."

He thought as he drew two lines after the Rasengan.

One line was labeled "Release Speed."

The other was "Compression, Increase."

And then he needed to find a way to integrate it better into his combat system, avoiding the mistakes of Naruto's early days, like maintaining the Rasengan and rushing recklessly.