Kakashi rubbed the back of his neck with resignation before letting out a long sigh.
"So… where should I start? Let's see…"
He glanced sideways at Satoru, who was watching him with crossed arms and an expectant expression, clearly impatient to see what he would be taught first.
The Hokage had already approved Satoru's request.
There was no way out: he had to become Satoru's teacher... even if he didn't like it...
"Do you know your chakra natures? If not, we'd better start tomorrow. Bring chakra papers and—"
"I know them," Satoru interrupted.
Kakashi sighed again, this time more deeply.
Apparently, he wouldn't get rid of the boy that easily.
"And they are…?" he asked disinterestedly, more out of politeness than genuine curiosity.
"Lightning, Water, and Earth," Satoru replied.
Kakashi blinked once. It wasn't common for a six-year-old to even know what elemental affinity was, let alone have three of them.
"Before I teach you anything, tell me… do you know the three basic techniques?"
Satoru looked at him, annoyed.
"Are you serious? Of course I know them."
"Don't take that as a silly question. Most kids your age don't even know these techniques exist" Kakashi replied with a shrug.
Satoru didn't respond. Internally, he found it absurd that something so simple could take years to learn.
"And how's your chakra control? Can you keep a leaf stuck to your body yet?"
"Probably better than you," Satoru wanted to say, though he held back.
"I've already mastered that exercise. I can also walk on trees and water."
Kakashi stayed silent, frowning slightly. Not because he doubted him, but because he didn't know what to teach next. It was clear the boy was far ahead of the curve.
The Hokage had only approved this mentorship in the hopes that Kakashi could influence him with the Will of Fire. Since Satoru had flat-out refused to attend the Academy, Hiruzen had no other option.
And yet, Kakashi had no idea what to teach him that he didn't already know.
"Do you even need me to teach you anything...?" he asked, almost incredulously.
"I found a lot of scrolls at home," Satoru said with a slight shrug. "The Senju Clan isn't exactly poor when it comes to techniques."
Especially Water Release, Wood Release, and Medical Ninjutsu.
Kakashi shoved his hands into his pockets and looked away.
"How's your Taijutsu?"
"Fine. Although I'm limited by my age," Satoru answered casually.
They both fell silent for a few seconds. Neither was particularly talkative, and the conversation was already getting heavy.
"Look," Kakashi sighed, "you'd better just tell me what it is you want to learn. Don't waste my time."
Satoru looked at him with a small smile.
"I want to learn Kenjutsu. Though, to be honest, the real reason I asked for you as a teacher... is to learn the Chidori."
Kakashi's eyebrow twitched slightly at that.
"Chidori isn't a technique to play with. It was created to kill. It's unstable and dangerous, with many flaws."
Satoru frowned and raised his voice just enough to make his complaint heard.
"Alright, then. I'll just take the early graduation exam soon, become a Genin, and start doing missions outside the village. What a shame it'd be for a cute little kid like me to die because he didn't have a decent offensive technique…"
Kakashi stared at him in silence, sighed once more… and knew his life had just gotten a little more complicated.
What Kakashi didn't know —didn't even suspect— was that Satoru had no intention of taking the early graduation exam.
In fact, Satoru had never had any intention of becoming a Leaf Ninja.
With the Nobility System, he knew it was only a matter of time before he left this world behind for good.
...
A few minutes later.
"Before I even consider teaching you the Chidori, I want you to understand its drawbacks," Kakashi warned. "Maybe, after hearing them, you'll change your mind about learning it."
Satoru sighed, resigned.
Kakashi was about to talk to him about the disadvantages of the Chidori… disadvantages Satoru already knew.
"First, to use the Chidori effectively, you need great speed and reflexes, which can be hard to maintain."
Kakashi looked at Satoru, who nodded without concern.
"Chidori consumes a large amount of chakra, which can leave the user drained if not used carefully."
Satoru scoffed, amused.
"Isn't that just your problem? Your chakra reserves are tiny compared to mine."
Kakashi remained silent. He knew Satoru wasn't wrong.
The Sharingan in his left eye, always active, consumed almost all his chakra, leaving him with minimal reserves.
"Lastly, the biggest drawback of the Chidori is its vulnerability. When used, the user moves so fast they lose peripheral vision, causing a tunnel vision effect. It makes them prone to missing incoming counterattacks."
Only then did Kakashi lift his ninja headband, revealing his left eye: the Sharingan.
"The day I obtained the Sharingan from the Uchiha Clan, I eliminated that drawback."
Kakashi couldn't help but show mild surprise when Satoru didn't react or ask any questions upon seeing his Sharingan.
"So let me get this straight," Satoru said, raising an eyebrow. "Because I'm not an Uchiha and don't have the Sharingan, you think I can't use the Chidori without risk?"
"Exactly," Kakashi replied without hesitation.
Satoru's sky-blue eyes gleamed for an instant. He took Kakashi's claim as a challenge.
Now more than ever, he wanted to master the Chidori and shut him up.
Had he lived in the Warring Clans Era, when the Senju and Uchiha were still enemies, Satoru would've been outraged at the thought that an Uchiha could achieve something he couldn't.
"Although…" Kakashi continued, staring directly into his eyes as he covered his Sharingan again. "Maybe you can learn it with those eyes of yours…"
Hokage-sama had ordered him to find out if Satoru possessed a new, unknown Dōjutsu, just as Itachi had suspected.
After Itachi reported his suspicions to the Hokage, the latter showed interest and assigned ANBU to investigate the matter more closely.
In the end, that responsibility fell to Kakashi.
Satoru smiled, amused, realizing Kakashi was trying to extract information from him.
"If that old bastard wants to know something, he can summon me and ask directly."
Kakashi frowned at how he referred to the Hokage, though he let it slide.
"But since I don't want to see his wrinkly face for a while, I'll tell you," Satoru finished with a shrug, as if the matter were unimportant.
"These eyes are known as the Rokugan. They're a Dōjutsu that's always active, like the Hyūga Clan's Byakugan. Though unlike the Byakugan, which has a passive form, my Rokugan remains active at all times."
Kakashi listened closely, not just because of his mission, but also due to growing personal curiosity.
"According to Senju Clan records, the Rokugan is an idiosyncrasy that's rarely inherited. The last Senju born with it was four hundred years ago."
Satoru wasn't lying. In this world, his abilities —from the Jujutsu Kaisen universe— had been given a unique backstory. Even he was surprised by it.
"And, apparently, there have never been two Rokugan users at the same time," he added thoughtfully.
Kakashi looked increasingly interested.
"What abilities does the Rokugan have…?" he asked in a murmur, unable to hold back his curiosity.
Satoru smiled mischievously.
"Why should I tell you?"
Kakashi blinked, thrown off by the answer and Satoru's sly grin.
Was he really going to leave him hanging?
"You… you're really not going to tell me anything else? I could literally die of curiosity right now…"
"Then die," Satoru replied, shrugging.
Kakashi rolled his eyes and fell silent.
"I'll just say the Rokugan doesn't fall behind the Sharingan. I can learn the Chidori without any problem."
Kakashi still wanted to refuse until he better understood the Rokugan… but the Hokage had given him direct orders to train Satoru.
And with nothing else left to offer him for now, he had no choice but to teach him the Chidori.
"Haa… Dealing with a genius kid is such a pain," Kakashi thought.