Year 37 of Konoha. The rain wouldn't stop.
A gray veil hung over the Hidden Leaf Village, pressing down on everything beneath it. The air carried a sharp mix of damp earth and rust. It was the smell of war.
The Second Shinobi World War was in full swing. Casualty reports flew back from the front lines, each one adding new names to the Memorial Stone. Even the Ninja Academy had no choice but to move its schedule forward and hold the graduation exam early.
On the academy's training grounds, a group of children barely ten years old stood in line, waiting for their turn.
"Next. Toru Nishikawa."
The chunin proctor, Daikoku, frowned as he called the name. He gripped a score sheet whose edges were soaked through by rain, his voice heavy with exhaustion and thinly veiled indifference.
From the crowd, a black-haired, black-eyed boy stepped forward.
He had neat features and a slight build. Unlike the other kids, who trembled with nerves, Toru's gaze was calm, flat as still water, carrying an appraisal that didn't match his age.
"Here."
His voice wasn't loud, but it was clear.
He walked up to the throwing line and pulled three shuriken from his pouch.
"This is the graduation exam. Why isn't he nervous at all?"
"Tch. He just aces the written test. Everyone knows his practical scores suck. His chakra reserves are pathetic."
Whispers spread through the crowd.
Toru ignored them. Instead of staring straight at the bullseye, he lifted his gaze slightly, scanning the treetops swaying in the wind, feeling the strength and rhythm of the raindrops hitting his cheeks.
Northwest wind. About level four. Humidity around ninety percent. High raindrop density, increased air resistance. Target distance, twenty meters. Adjust for wind drift and drop based on shuriken weight and shape.
The instincts from his previous life as a researcher kicked in.
Even in a world ruled by chakra, a fundamentally spiritual kind of energy, he still insisted on breaking ninjutsu down with science.
He didn't shake like the other students. He didn't use any flashy throwing stance.
Raise arm. Flick wrist. Release.
The motion was clean, straight out of a textbook. No extra chakra. Just raw muscle control and calculated angles.
The three shuriken traced strange arcs through the air.
Pushed by the crosswind, they seemed about to drift off target. Then, at the last moment, it was as if something invisible nudged their paths. Riding the wind, they spun faster.
Thunk. Thunk. Thunk.
Three dull impacts. The shuriken landed in a tight triangle around the red center of the target, perfectly placed.
"Full marks."
Daikoku raised an eyebrow, glancing at the usually quiet student with clear surprise. "Interesting. You actually used the wind. Your power's a bit lacking. You couldn't sink them three inches into the wood. But for a genin, this is solid."
That wasn't instinct. It was calculation, Toru corrected silently. Outwardly, he only nodded politely. "Thank you, sensei."
"Don't thank me yet. Next is the ninjutsu test." Daikoku pointed toward the testing equipment and a substitution log. "Use the technique you're best at. Attack or defense."
This was the real hurdle.
In this world, no matter how good your throwing was, without chakra it didn't mean much.
Toru took a deep breath and formed hand seals.
Ram. Snake. Tiger.
"Clone Jutsu!"
A light puff of smoke cleared, revealing two clones identical to Toru at his sides. To anyone paying attention, it was obvious they were unstable. Their outlines wavered, and one of them even had a left leg that flickered in and out.
The expectation in Daikoku's eyes vanished, replaced by disappointment. He marked the score sheet heavily.
"Chakra control is acceptable. Hand seal speed, point eight seconds. Standard." He shook his head. "But your chakra reserves are too low. Your total chakra is about average for your age, maybe even below. Maintaining two clones is already your limit, right?"
A hollow sensation spread through Toru's meridians. A clear sign his chakra was nearly spent. He released the jutsu and nodded, his face a little pale. "Yes."
He wasn't from the Uzumaki clan with their monstrous vitality. He didn't have the Uchiha's red eyes, the Hyuga's pale ones, or any kind of system backing him up.
In a world obsessed with bloodlines, Toru Nishikawa had drawn the most ordinary hand possible.
"Toru Nishikawa, you pass."
Daikoku handed him a metal forehead protector. There was no real congratulations in his tone, only a trace of blunt pity. "You made it, but I have to warn you. On the battlefield, no one's going to give you time to calculate wind direction. If your chakra reserves don't improve, once you're dragged into a prolonged fight, you'll die fast."
"Evaluation: mediocre."
The two words were written into the remarks column.
Toru took the headband, his thumb brushing over the cold Leaf symbol. He smiled.
Mediocre?
For someone who wanted to survive a battlefield like this, that was the highest praise.
Weak cannon fodder died early. Overpowered geniuses got targeted. Only the mediocre slipped through the cracks, buying time to live, buying time to turn the scientific theories in his head into something real.
"Next.... Minato Namikaze!"
The moment the name was called, the crowd stirred.
A boy with dazzling blond hair and a warm smile.
As he passed Toru, he gave him a friendly nod, flashing a bright, toothy grin.
"Your shuriken throw was amazing," Minato whispered, his blue eyes full of genuine curiosity. "How did you make that arc just now?"
"Instinct," Toru replied without thinking.
Minato chuckled and walked on.
The next two minutes belonged entirely to a genius.
Shuriken thrown in rapid succession, every hit dead on target. Some even collided midair, changing trajectory to strike blind spots.
The ninjutsu test was even more stunning. His Body Flicker was so fast Daikoku could barely follow it. His chakra reserves weren't on the Uzumaki level, but they far exceeded those of an ordinary student.
"S rank! Absolute S rank material!" Daikoku was shaking with excitement.
Off to the side, a black-haired boy with his arms crossed watched coldly, arrogance written all over his face. On the back of his clothes was an unmistakable red-and-white fan crest.
In the corner, Toru tied the headband around his arm. In his mind, another blueprint was already taking shape.
Low chakra is a hard limit, he calculated. If the software can't keep up, I'll have to compensate with hardware. Improved explosive tag formulas. Alloy ratios for chakra-conductive metals. And that project on systematizing chakra nature transformation… it's time to put that on the agenda.
A glint of feverish excitement flashed in his eyes.
"Ninja world," he thought, "are you ready for science?"