Sasuke sat alone on a worn bench near the edge of the Academy courtyard. Laughter echoed in the background as newly graduated students ran into the arms of waiting parents. Smiles, cheers, and proud tears filled the air like confetti. He looked at it all with a detached gaze.
He stared at the headband in his hands.
It was clean and brand-new. The polished metal gleamed in the sunlight, the engraved symbol of the Hidden Leaf catching the light. For most, it was a badge of honor, a sign of success, and the beginning of their ninja lives.
His eyes drifted back to the celebrating families, to the children beaming with pride as they were embraced and congratulated. Sasuke's fingers slowly curled around the headband, squeezing it tightly in his palm until the edges dug into his skin.
He stood up, and without a word, he turned and began walking.
'Itachi…'
The name echoed in his mind to the point of almost turning him mad. That man. The one who had ruined everything.
The headband disappeared into his pocket as his hand clenched around it once more. While others saw it as the start of their ninja life, Sasuke saw it as something else entirely. This was the symbol of the first step toward killing him and finally getting revenge for his family.
The Uchiha compound greeted him with its usual silence. It was isolated from the rest of the village; it sat like a ghost town, hollow and still. The homes, once full of life, now stood abandoned as silence reigned. It was suffocating, but Sasuke was used to it.
A lot of people had told him to move out of the compound. The Hokage himself had offered him a home elsewhere many times. A comfortable apartment closer to the village center, far away from here. He had refused. This place served as a reminder of why he needed to get stronger. He used this place to sharpen his hatred for the man who took everything away from him. Every nightmare he had, every time he felt lonely, every time he was lost. Everything. He blamed his older brother.
He passed his family's home without stopping, heading straight for the old Uchiha training ground. It hadn't been maintained since the massacre, weeds growing through the cracks and moss spreading across the stone. Still, Sasuke did his best to keep it usable. It was the one place he could truly focus.
While many were out celebrating with their families, he didn't have such luxury. He had to get stronger.
Sasuke trained relentlessly. He hurled kunai and shuriken with sharp precision, then tried to redirect them midair with another strike. Most attempts failed, the blades clattering uselessly to the ground. But he didn't falter. Day after day, his aim sharpened, and the misses grew fewer, but it was nowhere near as perfect as he wanted it to be.
Suddenly, his body started to feel warm.
He frowned a bit, shrugged it off, and continued his training. But as he kept training, the hotter his body would feel, to the point that he was starting to get uncomfortable.
He looked at the sky, which had turned a shade of orange, meaning the sun was about to set.
'Guess I am pretty tired...'
Even before today, he had been pushing his body to the limit every single day for the past few weeks. So it wasn't strange for his body to start feeling the strain of it all. He had decided to take it slow for the next week, as he wanted to meet his Jonin sensei in top condition.
He sighed before heading back home.
Strangely, his body kept getting hotter and hotter by the minute.
He had thought that he had worked himself to the limit before, but he had been walking back home for more than five minutes now. That was more than enough time for his body to have readjusted.
He then frowned even more.
He rarely got sick, and even when he did, it rarely affected him that much. But this was different. It felt different.
Suddenly, his vision blurred for a second, and he felt dizzy, almost to the point where he lost his balance.
This time, he was fully worried.
He rushed home immediately.
He entered the house and barged into the kitchen to grab a bottle of water, which he finished almost immediately. His body had gotten hot to the point that it was becoming unbearable. He was sweating heavily, and his head was starting to hurt.
Finishing his fifth bottle of water, he went to his room to rest.
As soon as he did, a head-splitting headache attacked him.
'Wha-what is going on?'
He was confused. What was happening? Did he push himself too hard while training?
No, that was not the case. Although he could feel his muscles spasm under stress, it wasn't to the point where they could reach this level of pain.
He continued to feel the heat rise in his body for a while before it suddenly came to a stop.
Something was definitely wrong. He promised himself he'd go to the hospital first thing in the morning.
But as he pushed himself up, a sudden wave of agony slammed into his skull. The headache was worse than anything he had ever felt. He collapsed back onto the bed, his body, fine only moments ago, now burning from the inside out.
Steam rose from his skin as sweat evaporated instantly. His muscles spasmed uncontrollably, each one screaming in pain.
'J-just… what's happening?!'
His vision blurred. Strength drained from his limbs with every passing second, the world slipping further away.
'Am I… dying?'
That single thought echoed in his mind. Nothing he had ever experienced felt this strange, this overwhelming.
'N-No!'
He clenched the bed sheets, trying to push himself upright.
"Not like this! Not now!" He couldn't allow himself to die before taking his revenge—not by some fever.
Suddenly, his chakra flared, coursing through him with a strange, raw intensity. It felt like his own, yet somehow purer, more concentrated.
'W-what…?'
Before he could even process it, the chakra vanished, draining the last of his energy. Darkness crept into his vision.
As he began to fade, a faint, mechanical voice echoed in his mind:
[Serial number: 134-5552-5233. Activating 15th-generation Nano Machine. Scanning the host's physical data. Commencing scan.]
'What… was that?'
That was the last thought before unconsciousness claimed him.
[Scanning complete. Emergency! Emergency! An unrelated energy source has been found. Gathering data... Data found. Chakra energy has been scanned. Beginning the adaptation phase. Duration: 16 hours.]
[Releasing anesthesia. Body reconstruction underway. Phase duration: 13 hours.]
With that, Sasuke's body began to change...