A drop of fresh blood slipped from beneath Kakashi's mask.
He struggled briefly, but as Muzan's black thorns coiled tighter around him, resistance gave way to resignation.
"Damn it, brother… I didn't expect your Kekkei Genkai to give you this much power."
There was no hatred in his voice—only a faint trace of envy.
Both were sons of the Hatake clan, yet only Muzan had awakened a special bloodline ability.
Kakashi steadied his breathing and looked him in the eyes.
"Don't get cocky, brother. I'll master the Hatake Sword Style even better than you. Next time, I'll cut through those thorns!"
Muzan smiled faintly. "Hahaha… I look forward to it."
But their brotherly moment was short-lived.
"WHAT have you two done!?"
The furious roar of Sakumo Hatake echoed across the courtyard.
He had sensed the sounds of fighting earlier, assuming it was harmless practice—maybe a few Fireballs exchanged at most.
Yet when he arrived, the scene nearly made his heart stop.
The once-pristine Hatake garden was in ruins. The walls were cracked, the courtyard gouged with claw marks, and even the cherry tree he'd "borrowed" from the Hokage's mansion now stood stripped bare—nothing left but a naked trunk.
"You two brats! Do you have any idea what you've done!?"
Konoha's White Fang—one of the most feared shinobi in the world—now looked less like a legendary hero and more like an exasperated father forced to clean up after his kids.
"Get over here and fix this mess!" he shouted, finger trembling with rage.
"Sorry!" the brothers chorused, bowing in unison.
---
Later, when Muzan calmly demonstrated his Kekkei Genkai, Sakumo's anger gave way to grim fascination.
"So this is your Kekkei Genkai… 'Black Blood Thorns.'"
Dark spines bloomed from Muzan's arm at his command, glinting like steel. Even Sakumo's expression hardened.
"That's a dangerous ability. If a genin fails to dodge, they'd be dead instantly."
He sheathed his blade and straightened.
"From now on, both of you will train together—ninjutsu and the Hatake Sword Style. I'll personally oversee your progress."
With a Kage-level shinobi as their teacher, the brothers' growth accelerated rapidly.
Their paths diverged.
Kakashi, ever the prodigy, focused on sharpening his taijutsu through constant sparring with Might Guy, the so-called "Green Beast."
He remained the Academy's brightest star—admired, envied, and relentlessly pursued by fangirls.
Muzan often wondered, watching from the sidelines,
If Kakashi's this popular, how does he end up single in the future?
Maybe it really is the dead-fish eyes…
While his brother basked in fame, Muzan preferred to remain invisible—
the quiet figure who spent every spare hour buried in books at the Konoha Library.
His interests had shifted toward medical ninjutsu and theory.
A year of study paid off: in both medical knowledge and "Will of Fire" philosophy classes, he ranked first in his year.
Among his peers, he earned a new nickname—
"Bookworm Muzan."
---
"Hey, Bookworm Muzan!"
A voice called from behind. It was Obito, waving cheerfully despite his perpetually messy hair.
He'd felt guilty ever since the day he'd accidentally tugged on Muzan's sleeve and caught a glimpse of the boy's scarred, pale skin—an incident that had ended with Kakashi beating him up for "picking on his brother."
After learning about Muzan's mysterious skin condition, Obito began visiting him regularly.
As one of the class's underperformers, he found it strangely comforting to talk to the quiet "invisible" boy under the tree.
Besides, Rin adored Kakashi—just like everyone else did.
That thought burned more than any training injury.
Damn you, Kakashi…
Muzan closed his book and leaned back against the tree trunk, watching Obito sigh and kick at the dirt.
"Why would I be bothered?" he said casually. "My brother's strong. That just means I have more time to study."
"But still…" Obito frowned, unable to argue.
He knew Kakashi's talent was monstrous—blinding, even. Anyone standing beside him seemed dull in comparison.
To Obito, Muzan looked like a failure who'd accepted mediocrity.
Feeling oddly motivated, Obito stood up and clenched his fists.
"Just you wait! Once I awaken my Sharingan, I'll surpass Kakashi! And when that happens, I'll make you my subordinate!"
Muzan nearly choked on laughter. "Hah. Ambitious. But you'd better work hard, Obito! If Kakashi surpasses you again, I'll just stick with my brother instead."
As he said this, Muzan's smile stiffened for a moment.
Be Obito's subordinate? he thought wryly. Don't tell me I'd end up standing behind Madara one day…
He turned his gaze toward the massive tree behind Obito—and froze.
A faint, unnatural chakra signature pulsed from within.
It blended almost perfectly with nature's energy.
If not for his acute senses, even he would have missed it.
"So… Madara's already marked Obito, huh?"
The realization made his expression darken.
That subtle chakra belonged to White Zetsu—a creation of Madara Uchiha himself.
How reckless, Muzan thought. To infiltrate Konoha of all places…
This was not the weakened Konoha of later years. Even now, multiple Kage-level shinobi resided in the village.
For Zetsu to sneak in unnoticed—it was bold, but dangerous.
Muzan had no intention of interfering with Madara's grand plan.
The old man's body was barely alive; he'd probably pull his life-support tubes out soon just to reunite with Hashirama.
As long as Madara didn't try to manipulate Kakashi, Muzan was content to leave things be.
But…
"If White Zetsu's here," he murmured, "this is a good chance to test something."
—
The truth of Muzan's bloodline was simple:
he didn't need to kill humans to grow stronger.
But Zetsu—a half-organic, half-artificial being—was another matter entirely.
He sent Obito off with a light excuse, then casually walked toward the base of the great tree.
With his harmless smile and calm chakra, he fooled even Zetsu's senses.
After all, who would suspect a frail-looking Academy student?
Then—
"Blood Demon Art: Flesh-Devouring Maw!"
His arm twistedly transformed into a pulsing mass of muscle and sinew, sprouting a gaping mouth lined with fangs.
Before Zetsu could react, the monstrous appendage surged forward, devouring both the tree and its hidden occupant in one violent motion.
Zetsu never stood a chance.
His strength lay not in combat but in cloning and spore-based manipulation. Against Muzan's overwhelming regeneration and bloodline power, he was nothing.
If Muzan truly went all out, he could probably match—or even kill—a chūnin-level shinobi.
But the most terrifying part was his immortality.
Even Hashirama Senju's regeneration would pale beside Muzan's.
Crunch. Crunch.
The sound of chewing echoed softly through the clearing.
Muzan felt a wave of warmth spread through his veins—a new, alien chakra merging with his own.
"Ahhh…" He exhaled with a low sigh, his voice trembling with satisfaction.
"That feels… incredible. If I devour more of these Zetsu, my strength will skyrocket."
---
Meanwhile, deep in an underground cavern far from Konoha—
White Zetsu's other body suddenly froze.
Its expression shifted from lazy amusement to shock.
"My clone… just got destroyed."
Madara's old, cracked voice broke the silence. "What happened?"
"I—I don't know. Someone in Konoha killed it instantly. When did they get a sensor ninja that powerful?"
Madara frowned, his frail body supported by tubes that hissed softly with each breath.
He hadn't paid much attention to Konoha for years; his focus had been entirely on Amegakure and the coming war.
"The Uchiha boy is crucial to my plan," he muttered. "Replace that meddling old woman who's been watching him… and make sure Obito sees this world's darkness."
"Yes, Madara-sama."
---
Back in Konoha, poor Obito had no idea he'd already caught the eye of the ancient Uchiha patriarch.
He'd barely left the training grounds when an explosion shook the air behind him.
Instructor Nobibei sprinted to the scene, only to find the great tree split clean in half—its core torn apart as though by some massive creature.
And beside it stood Muzan, hands behind his back, face perfectly calm.
"This kid really is going to give me a heart attack," Nobibei muttered.
He'd long since realized how terrifying Muzan's talent truly was—his chakra control was unnaturally precise, his reserves immense.
If not for the boy's desire to remain "invisible," he might already have outshone Kakashi himself.
But Nobibei understood what was at stake.
With a quick glance around to make sure no one else had seen, he gestured for the other students to leave.
"At this rate, you'll tear down the whole Academy, kid," he sighed.
"Anyway, about that favor you asked—the one involving the hospital… I've made some progress."