It was Sunday, the Academy’s weekend holiday. The backyard of the Uchiha family home had been transformed into a private training dojo.
Yuji stood in the center of the yard, facing his father, Uchiha Sagato. As a Jonin serving in the Konoha Military Police Force, Sagato rarely had time off, but today happened to be one of those precious weekends when he could devote his attention to training his son.
On the wooden veranda, Sayaka sat neatly beside Aunt Uchiha Ayako, the family’s caretaker. An illustrated storybook rested on her lap, opened to a page filled with smiling rabbits. Yet her eyes never once drifted toward the book. Instead, they remained glued to the sparring match unfolding before her.
To Sayaka, she couldn’t even see two people anymore.
She only saw two blurry figures flashing across the training ground faster than she could blink. Tiny sparks of lightning flickered wherever they moved.
"Wow... Dad and Big Brother turned into really fast fireflies," Sayaka said innocently.
Ayako covered her mouth, trying not to laugh.
"That’s called taijutsu, Sayaka. Not fireflies."
"Oh..."
Sayaka nodded with complete seriousness.
"So... they’re ninja fireflies."
She happily swung one of her crayons around like it was a tiny sword.
In the middle of the yard, Yuji and Sagato faced each other in silence.
Sagato stood with the composed posture of an experienced Military Police Jonin. His sharp eyes examined Yuji as though he were interrogating a dangerous criminal instead of preparing for a family sparring match.
Yuji took a slow breath.
His Sharingan activated.
Two tomoe spun gracefully within his crimson irises.
At the same time, chakra surged through his body.
Basic Lightning Release Mode.
Blue chakra instantly wrapped around him while small arcs of electricity danced across his skin. His long ponytail floated upward under the current of chakra, every strand standing on end as though he had just hugged a lightning rod.
Sagato narrowed his eyes.
"...That technique."
"It resembles the Raikage’s Lightning Release Armor from Kumogakure."
Yuji raised both hands casually.
"No, Father."
"I developed this from the Lightning Body Technique. It’s my own version."
Ini butuh lebih banyak chakra"
"Tapi lebih cepat dan kuat."
Sagato sighed.
"Bright enough for the neighbors to dry their laundry without sunlight."
"If the Military Police ever needs emergency floodlights..."
"...I know exactly who to call."
Behind them, Sayaka hid her smile behind her picture book, though her sparkling eyes never left her brother.
The match began.
Sagato moved first.
Every step reflected years of experience. There were no unnecessary movements, no flashy poses. Only precise punches, sweeping kicks, and joint-lock techniques that would make anyone think twice before melawan hukum.
Yuji disappeared.
His enhanced speed allowed him to dodge each strike effortlessly. Every step left behind faint streaks of blue light across the ground.
Sagato’s expression slowly changed.
Without warning...
Three tomoe bloomed inside his Sharingan.
His gaze locked onto Yuji with unnerving intensity.
It was the exact same stare he used when cornering dangerous suspects during interrogations.
Yuji didn’t flinch.
Sagato suddenly closed the distance and launched a straight punch toward Yuji’s chest.
Yuji intercepted it with an arm coated in lightning.
Boom!
A sharp explosion echoed through the backyard as sparks scattered like a failed fireworks display.
"Impressive," Sagato admitted.
"Fast..."
"And incredibly powerful."
His hands immediately formed seals.
"Fire Release: Great Fireball Technique!"
A massive sphere of blazing fire roared toward Yuji.
Yuji vanished.
He reappeared at the far edge of the yard, narrowly avoiding the flames.
But before he could recover—
Bang!
A heavy punch slammed directly into his stomach.
Sagato had already used the Body Flicker Technique to appear in front of him.
Yuji flew backward like a cannonball before crashing violently into the concrete wall surrounding the backyard.
Dust exploded everywhere.
Sagato watched calmly.
Then...
Yuji’s body dissolved into grains of sand.
"...Genjutsu."
Sagato’s eyes narrowed.
When?
Before I even activated my Sharingan...?
He slipped me into an illusion right at the beginning...
Despite his surprise, Sagato remained perfectly composed.
Without turning around, he blocked another punch aimed at the side of his head.
The real Yuji had already appeared behind him.
His two-tomoe Sharingan spun rapidly.
Yuji pivoted and unleashed a low sweeping kick wrapped in crackling lightning.
The impact shattered the ground beneath him.
Thin fractures spread across the training yard.
Sagato calmly leaped backward.
"Good."
"Now it’s my turn."
With a single-handed seal, another enormous fireball erupted toward Yuji.
This time...
Yuji charged directly forward.
Lightning completely enveloped his body.
His chakra reserves dropped dangerously close to empty.
He dodged through the inferno itself.
His hair stood even straighter now, making him look like he had just walked out of an electrical salon disaster.
"Kyaa!"
Sayaka pointed excitedly.
"Big Brother’s becoming lightning barbecue!"
"Sayaka..."
Ayako sighed.
"Sorry..."
"But Big Brother is amazing!"
Yuji emerged safely from the side of the blazing flames.
He smiled.
"Lightning defense against fire..."
"Effective."
Sagato let out another long sigh.
"You really aren’t afraid of getting that close to a fireball."
Without another word, Sagato accelerated.
His speed increased dramatically.
Fortunately...
Yuji’s Sharingan could now read every subtle movement.
The instant Sagato shifted his shoulder—
Yuji already knew where the next punch would come from.
Their fists collided repeatedly.
One exchange.
Two.
Three.
Neither landed a decisive hit.
They were simply too fast.
Still...
Sagato was clearly holding back.
Eventually, he raised one hand.
"Enough."
Yuji stopped immediately.
The lightning surrounding his body faded away.
His chakra had been nearly exhausted after fighting at full intensity for almost an hour.
His long hair finally dropped back into place.
Breathing heavily, he glanced toward the transparent system screen floating before his eyes.
[Mission Complete: Train at Full Power]
Reward: +1 Chakra Point
Warm chakra flowed back into his body.
Not much...
But enough to restore a little strength.
Yuji sat down on the ground, drenched in sweat.
Sagato walked over and patted his shoulder.
"You’re strong."
"Fast."
"And your use of genjutsu in actual combat has improved considerably."
He paused.
"But that lightning technique burns through chakra far too quickly."
"Don’t worry," Sagato continued.
"As you grow older, your chakra reserves—which are already unusually large—will continue to increase."
"Never forget."
"We are Uchiha."
Yuji nodded.
"I know."
"This mode consumes almost three times as much chakra as the original Lightning Body Technique."
"But..."
"My speed increases dramatically."
"And my defense becomes much stronger."
Sagato rubbed his chin thoughtfully.
"Hmm..."
"That’s true."
He looked suspicious again.
"You’re absolutely certain this isn’t Kumogakure’s Lightning Release?"
Yuji laughed.
"When exactly have I ever visited Kumogakure?"
Sagato nodded slowly.
"...Fair point."
The two sat together at the edge of the training ground.
Ayako arrived carrying towels and cold water.
Sayaka proudly ran over while holding her drawing.
"Dad!"
"I drew you!"
Yuji looked at the picture.
There was a large monkey-like figure standing beside a smaller monkey whose hair stuck straight upward while zigzagging lightning surrounded its angry face.
"...That’s Dad?"
"And that’s me?"
Sayaka nodded proudly.
"The title is..."
’Dad Who Likes Beating Up Big Brother Yuji.’
Sagato gently patted her head.
"I’ll keep it."
"I’ll hang it in my office."
Yuji couldn’t help laughing.
After finishing his water, Sagato looked at him again.
"By the way..."
"Where exactly did you learn that lightning technique?"
"...Don’t tell me you invented another one."
"I did."
Yuji answered simply.
Sagato stared at him for several silent seconds before sighing once more.
"Let’s go again."
"One more round."
"But this time..."
"No lightning."
"Practice the fundamentals."
"On the battlefield, you won’t always have enough chakra to rely on ninjutsu."
Yuji groaned dramatically.
"Father..."
"You’re cruel."
"If you depend entirely on lightning..."
"You’ll die the moment your battery runs out."
"That’s an unfair metaphor."
"I’m not a toy."
Sagato answered without changing his expression.
"You’re my toy."
The second round began.
Without Lightning Release, Yuji immediately felt slower.
Sagato pressed the attack relentlessly using practical Military Police techniques—joint locks, throws, sweeps, and efficient close-quarters combat.
Punch.
Block.
Throw.
Yuji hit the ground twice.
Dust clung to his cheeks.
"Kakak lost!"
Sayaka shouted.
"It’s part of the training," Ayako reminded gently.
Sayaka peeked through one eye.
"...It still looks like punishment."
Even so...
Yuji adapted quickly.
Without relying on Sharingan, he gradually learned Sagato’s rhythm.
He copied the footwork.
Redirected momentum.
Read the timing.
Finally—
A perfectly timed sweep knocked Sagato onto his back.
Since Sagato wasn’t using chakra and was intentionally holding back for his exhausted son, the technique landed cleanly.
Lying on the ground, Sagato burst into laughter.
"You really do learn frighteningly fast."
Yuji offered him a hand.
"You fight like a marketplace thug who enjoys beating children."
Sagato accepted the hand and stood up.
"Good."
"That’s the most honest compliment I’ve received all year."
"I’ll add it to my official report."
Their training finally came to an end.
The sun had climbed high into the sky.
Covered in sweat and dust, the two Uchiha looked less like elite shinobi and more like muddy statues...
Or perhaps...
Exactly like the monkeys in Sayaka’s drawing.