Chapter 49: Tsunade's Teachings
One day, after seeing Nan use Chidori to shatter a large boulder, Tsunade could no longer hold back her curiosity.
"That Lightning Release technique… what exactly is it? I've never seen it before."
Nan stopped his training and replied calmly:
"It's a jutsu I developed with Kakashi. Over time, we created two versions.
The one I used earlier is my personal version—a Lightning Release taijutsu technique I call 'Divine Speed.'
The version you just saw is Kakashi's—it's called Chidori."
Tsunade nodded, then narrowed her eyes.
"There's no doubt—it's an extremely effective combat jutsu.
But you're a medical ninja. Why would you need such a powerful offensive technique?"
Nan paused, considering his answer.
In truth, he didn't have any grand reason. In his past life, he was just a fan of the Naruto series—fascinated by its many unique jutsu. He'd often fantasized about mastering them all, becoming an all-powerful shinobi.
Now, by a twist of fate, he had actually come to live in the Naruto world. So naturally, he wanted to indulge in that collector's obsession and fulfill his childhood dream.
But if he said that out loud, there's no way Tsunade would understand. He needed a reason that made sense within this world—something that fit the tone of the shinobi.
"My dream has always been to become Hokage," Nan said sincerely.
"So I've always asked myself—what kind of person is truly worthy of that title?"
"At first, I believed that the Hokage should be someone who stays behind the front lines—
someone who protects the village from the shadows, a strong and reliable pillar of support.
That's why I committed myself to learning medical ninjutsu."
Of course, the real reason he'd started medical training at age three was because his mother told him to.
But that wasn't something worth explaining now.
"After my mother passed away, my perspective changed.
I realized a Hokage shouldn't just be a shield.
They should also be a hero who stands at the very front—cutting through danger to protect their comrades."
"To be that kind of person, I knew I had to become stronger.
That's why I've been pushing myself to train harder, master more jutsu, and develop real combat power.
So that when danger comes, I'll have the strength to protect more people."
Nan wasn't completely making it up. These thoughts—though scattered—had indeed passed through the mind of his original self.
And after awakening in this body, he merged those thoughts with his own experiences and reflections from his previous life.
The result was a statement that made perfect sense for someone living in the world of shinobi.
Sure enough, Tsunade looked pleased with his answer.
She found his explanation perfectly reasonable. Nan's maturity did catch her a bit off guard, but considering how early shinobi matured in the ninja world, it wasn't all that unusual.
Still, she felt the need to remind him.
"You know, I once laid down three golden rules for Konoha's medical-nin."
Nan nodded. His mother had taught him those rules before he began his medical training.
"Then you should remember the second rule—
'Medical-nin must never fight on the front lines.'
A medical ninja's job is to protect their comrades after they've fallen.
To do that, you must first protect yourself."
Tsunade's tone grew serious.
"So, I don't recommend that you—as a medical ninja—put yourself directly in harm's way."
Nan understood. The three rules Tsunade had established were important, and thanks to them, he had never been assigned a direct combat mission.
Even during the battles in the Land of Wind, he remained in the rear—never engaging in actual fighting.
And honestly, he preferred it that way.
Given his personality, he was more than happy to lay low and survive quietly.
If possible, he'd like to make it to the end of the story without ever stepping onto the battlefield.
Even if Kaguya showed up—or events reached the Boruto era—he'd rather avoid getting involved at all.
Of course, Nan couldn't say any of that out loud—it would completely contradict everything he had just told Tsunade about his dream of becoming Hokage.
So instead, he said:
"That's exactly why I developed Divine Speed.
Unlike Chidori, which focuses on a single lethal strike, Divine Speed isn't very destructive.
Its purpose is to keep me in a sustained state of high speed, making it hard for enemies to land a hit.
I see it as a way to break free from the limitations of the three medical ninja prohibitions."
In truth, Nan had originally created Divine Speed just to compensate for his lack of physical speed.
He hadn't been thinking that far ahead at the time—it was simply convenient now to use it as an excuse in front of Tsunade.
He didn't actually expect her to accept it.
To his surprise, Tsunade nodded thoughtfully.
"You're right. There are situations where even medical-nin are forced onto the battlefield.
In those cases, they do need special techniques to survive.
Your approach makes sense to a degree... but the effect is still quite limited."
Then her tone shifted.
"Extreme speed might reduce your chances of getting hurt, but it doesn't eliminate them.
And if you're the only medical ninja on the team, the moment you get injured, the whole squad is in danger.
So let me ask you—what would you do then?"
Nan hesitated.
He did have a backup plan: his Yin-Yang Release: Phantom Body Technique, which not only possessed powerful healing abilities but could even take damage on his behalf.
With both healing and defense capabilities, Nan was basically untouchable.
But revealing the existence of his Mangekyō Sharingan to Tsunade was out of the question—so for now, he stayed quiet.
Seeing his silence, Tsunade continued:
"There's only one way a medical ninja can fight on the front lines without hesitation.
It's a rule that goes beyond the original three—the Fourth Principle of medical-nin:
Only those who have mastered the Strength of a Hundred Seal and Creation Rebirth are qualified to ignore the standard prohibitions and engage directly in combat."
Nan was stunned.
Those words… weren't they the exact ones Tsunade said to Sakura Haruno in the original story?
Now she was saying them to him?
Does this mean... Tsunade is planning to pass down the Strength of a Hundred Seal to me?
He acted surprised and quickly responded with eager excitement:
"There's actually a method like that?
Tsunade-sensei, would you be willing to teach me the Strength of a Hundred Seal and Creation Rebirth?"
Tsunade gave a soft smile and nodded.
"From what you told me earlier, I can tell you're serious—
even as a medical ninja, you're determined to fight for those you care about.
So yes, I'll teach you both techniques.
I'll also teach you the Yin Seal: Release, you'll need to master before you can use them."
This time, Nan couldn't contain his joy.
He jumped up in excitement—and for once, it wasn't an act.
Originally, he'd only hoped to learn some advanced medical ninjutsu from Tsunade.
He never imagined she'd treat him as a true disciple—entrusting him with her most powerful, secret techniques.
But the more he thought about it, the more it made sense.
Tsunade had always wanted to find a worthy successor to her legacy.
In the original timeline, she chose Sakura Haruno, while Shizune—despite being loyal—never received those abilities.
It wasn't favoritism. Shizune simply didn't have the talent for it.
Now, in this life, Tsunade had encountered someone even more gifted—himself.
It was only natural that she would want to pass on her deepest techniques.
As for whether Tsunade would still take Sakura as her apprentice in the future…
That wasn't something Nan worried about.
If it came to that, he could always take Sakura as his disciple.
Truth be told, Tsunade had been considering passing down the Yin Seal and Creation Rebirth for some time.
From the moment she met Nan, she saw reflections of her younger brother Nawaki and Dan in him.
And after today's conversation—hearing Nan's ideals and determination—that resemblance became even clearer.
She could almost see Nan walking the same path as they had… and possibly meeting the same tragic fate.
That thought shook her.
So she made up her mind—
She would teach him everything.
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