Early the next morning, before the sun had even managed to burn the mist off the rooftops of Konoha, Evan Kamiyo was awakened by a rhythmic, heavy knock at his door.
When he pulled it open, he found Inuzuka Hana standing in the hallway. She looked like she hadn't slept, her hair slightly more disheveled than usual, but her eyes were bright. At her feet sat a small, young ninja dog, sitting with a level of obedience that bordered on the unnatural.
"You're lucky," Hana said, her voice a bit husky from the morning air. "This one just came through the clan's internal breeding program. Temperament passed. Compatibility passed. Usually, the elders hoard these for the main family branches, but I made an executive decision."
Evan crossed his arms, leaning against the doorframe as he studied the animal. It was small, still clearly a puppy, but its skeletal structure was sturdy and its posture was rock-steady. It had a white coat with sharp black patches, and a distinctive thin black stripe ran straight down its forehead like a lightning bolt.
What struck Evan most were the eyes. They were pure, liquid black, and they weren't filled with the typical frantic energy of a pup. They were calm, almost observant. The dog stared back at Evan without blinking, its head tilted slightly as if it were reading the flow of his chakra.
"…So this is what a ninja dog looks like," Evan muttered, his medical mind already cataloging the creature's heart rate and respiratory rhythm.
Hana raised an eyebrow, a small smirk playing on her lips. "What, you expected something cuter? Something with a ribbon?"
Evan crouched down, extending a hand palm-up. The dog didn't bark or shy away. It leaned forward, sniffed his skin once with a wet, cold nose, and then pressed its forehead firmly against his palm. It was a gesture of total acceptance, a silent contract signed in a heartbeat.
No fear. No excitement. Just a cold, calculated recognition.
"What breed is it, exactly?" Evan asked, feeling the dense muscle beneath the dog's fur.
"Officially? It's classified as an Inuzuka combat variant, Gen-3," Hana replied, leaning against the opposite wall. "Unofficially, it's just… a dog. The ninja world never bothered with standardizing breeds the way civilians do. We care about results, not pedigrees."
She paused, her expression softening. "The bloodline is clean. Strong vitality. There's a faint trace of northern wolf ancestry in this litter, which explains the eyes and the quiet temperament."
Evan nodded, his fingers scratching behind the dog's ears. "I don't need it to fight. I'm not looking for a four-legged weapon."
"That's good," Hana said, her voice dropping to a more serious register. "Because forcing a dog to fight before it's ready ruins the bond. It turns them into tools, and tools eventually break. An Inuzuka dog is a partner."
Evan looked into those black eyes again. "I don't plan to use it as a weapon. I need a sensor. Someone to see the things I'm too busy to look at."
The dog's tail wagged exactly once. A sharp, singular motion of agreement.
Hana smiled faintly, pushing off the wall. "Feed it well. High protein, minimal salt. Train together, but for the love of the Sage, don't overdo the chakra exposure. Their systems are sensitive."
When she turned to leave, the dog didn't wait for a command. It stood up and followed Evan inside the apartment as if it had been living there for years, claiming its space with a quiet, unassuming gravity.
It stayed close. Too close. Every time Evan turned around, the dog was there, a silent shadow at his heels.
Evan stopped walking in the middle of his kitchen. The dog stopped instantly, sitting back on its haunches.
"…You're going to stick to me like this, aren't you?" Evan sighed.
The dog just tilted its head, its black eyes reflecting Evan's own face.
Evan exhaled, a sound of mock-exasperation. "Troublesome."
By noon, the strangeness of the bond became even more apparent. No matter where Evan moved in the small apartment, the dog adjusted its position perfectly to maintain a line of sight. When Evan sat at his desk to practice chakra control, the dog lay quietly at his feet, its breathing syncing with his own.
When he practiced hand seals, the dog's ears twitched with every flick of his fingers. When he meditated, the dog slept—but its ears remained active, swiveling toward every creak in the floorboards.
This wasn't the needy attachment of a pet. It was synchronization.
"I'll give you a name," Evan said quietly that evening, watching the sunset bleed red across the training grounds outside his window.
The dog perked up, its body tensing with anticipation.
"…Kuro," Evan decided. Black. Simple. Functional.
The dog barked once—a sharp, satisfied sound that echoed in the quiet room.
Half a month passed in a blur of routine. Evan spent his mornings at the hospital, his afternoons with Kakashi, and his nights in the secluded training grounds with Kuro.
Growth had not stalled, but it had reached a plateau of stability. His physical attributes rose with every workout. His chakra density increased with every meditation session. His Sage Body adaptation continued to weave itself into his DNA.
But his ninjutsu progress… it lagged. And for someone like Evan, "lagging" was an insult to his intelligence.
The Rasengan remained a turbulent, unstable mess that collapsed after three seconds. The Chidori remained a theoretical blueprint that burned his palms without producing a strike.
Back in the original timeline, Naruto had brute-forced the Rasengan in weeks through sheer, unyielding willpower and clones. Sasuke had mastered the Chidori under Kakashi's personal, one-on-one tutelage for a month.
Evan had neither the luxury of infinite chakra nor the luxury of a teacher who would hold his hand through every seal. He was an anomaly, and he had to find his own way.
He opened the System panel in the dim light of the moon.
Credits: 23,816
His gaze moved down the list of potential upgrades, skipping over the minor stat boosts and equipment. Then, he stopped.
[Nine-Tails Chakra Seed — Available for Exchange]
A warning in deep crimson text followed the entry immediately:
The tailed-beast chakra seed cannot be fused unless the host possesses sufficient mental stability. Forced fusion may result in chakra collapse, irreversible neural damage, or death.
Evan clenched his jaw, his eyes cold. "Of course it wouldn't be simple. Nothing in this world is a free lunch."
He scrolled further down, his eyes landing on a different category.
[Exchange option available: Ninja Nature — Lightning] [Effect: Ninjutsu efficiency +30%, Chakra recovery +30%, Nature Transformation Mastery speed +50%] [Cost: 8,000 points]
Lightning. Everything in his current path circled back to the spark.
Evan hesitated. Spending points now meant slower long-term growth for his core attributes. It felt like taking a shortcut. But he looked at his scorched palms and thought about the "Blood Moon" that was coming for the village.
"…If I keep waiting for the perfect moment to move, the world will move without me," he whispered.
He tapped the screen. Confirm exchange?
"Yes."
The system didn't chime this time. It roared.
Pain followed instantly—not a physical strike, but an internal, crushing pressure. It felt as if his veins were being filled with liquid glass. His chakra surged violently, condensing in his tenketsu, vibrating at a frequency that made his teeth ache.
His nervous system was being rewired, the pathways being scorched and then rebuilt to handle the high-voltage nature of lightning. Evan dropped to one knee, his forehead hitting the cold grass, his teeth gritted so hard he thought they might shatter.
Kuro rushed forward, barking sharply, his fur standing on end from the static electricity leaking off Evan's body.
"It's fine," Evan rasped, his voice sounding like grinding stones. "Stay back, Kuro. Don't touch me."
Slowly, the sensation stabilized. The heat receded, replaced by a strange, humming coolness. The power didn't explode outward; it aligned inward.
Evan opened his eyes. The world looked different. Sharper. He could hear the hum of the village's power lines, the static in the air, the friction of his own clothes. Chakra responded to his thoughts instantly, moving without the usual "lag" or resistance.
"…So this is Ninja Nature," he breathed.
It wasn't a god-level explosion of power. It wasn't omnipotence. It was something far more dangerous: absolute efficiency.
Evan laughed once—a quiet, breathless sound of realization. "I get it now. I've been trying to force the river, when I should have been the lightning that chooses the path of least resistance."
That night, he didn't go home. He returned to the center of the training ground before the first light of dawn.
He didn't bother with a complex stance. He just stood there, breathing. He formed the seals for the Rasengan—not out of habit, but out of understanding.
Chakra rotated. It didn't just spin; it vibrated at a specific harmonic frequency. It focused.
A sphere of energy formed in his palm. It didn't wobble. It didn't collapse. It hissed with a stable, terrifying power, glowing with a faint blue light that illuminated the trees.
Rasengan.
It wasn't perfect yet, but it was real. It was no longer a theory; it was a tool.
Evan exhaled slowly, the light of the technique reflecting in his eyes. Kuro sat beside him, his tail still, watching the swirling sphere with an expression that looked remarkably like pride.
The horror of "Ninja Nature" wasn't the raw power it provided. It was how quickly a person could reach the heights of lethality if they were willing to pay the price in points and pain.
Evan Kamiyo had just taken his first irreversible step toward the top of the food chain. He was no longer just a medic with a hobby; he was a natural disaster in training.