When Aoki Tatsuya opened his eyes, he expected chakra. Jutsus. Shinobi headbands and flashy hand signs. The world of Naruto, as he knew it from the anime back on Earth, was a place of martial prowess, tragic backstories, and epic power-ups.
But this wasn't that.
The first thing he saw was a pair of moaning civilians, completely naked, going at it on the side of the street like it was the most normal thing in the world. Behind them, another couple. And another. There were even small shaded stalls, open-air taverns, and open rooftops where people were tangled up in loud, passionate embraces.
"The hell?" Tatsuya had muttered.
His first instinct was to assume he was dreaming. Or had gone insane. But then the memories hit him—hard and fast, like a genjutsu crashing through his brain. They weren't his, but those of the boy whose body he now inhabited. A young man also named Aoki Tatsuya, just turned eighteen, and freshly eligible to join the Ninja Academy.
Yes. You heard that right.
In this world, the Academy wasn't for children. It was a prestigious institution reserved only for those who reached adulthood.
Why?
Because chakra—the very source of ninjutsu, taijutsu, and genjutsu—could only be awakened through one thing:
Sex.
That's right. Chakra couldn't be unlocked through meditation or breathing exercises or bloodlines. It was biological. Intimate. The very first time someone had sex, their chakra pathways would open like a floodgate, awakening their spiritual and physical potential. And from there, the more sex they had, the stronger their chakra became—albeit slowly.
It was insane. It was degenerate. And yet, to the people here, it was normal.
Tatsuya stumbled into his small apartment, locking the door behind him as if that would keep the madness outside. He was panting, heart racing. He touched his face, his chest. Still real. Still him.
He looked in the mirror and saw his new reflection: light eyes, spiky mauve hair, lean build—youthful, but athletic. He was supposed to be a fresh adult, someone who had abstained his entire life for this moment.
Because here, sex was strictly forbidden before the age of eighteen. Anyone caught engaging in it too early would be banned from the Academy, from unlocking chakra at all. They would live as regular civilians for life. It was the ultimate taboo, the sacred law.
So they were taught everything from a young age: anatomy, pleasure, techniques, even theory on chakra-linked compatibility. But they were told, again and again:
"Wait. Wait until you're of age. Or be powerless forever."
Just as Tatsuya sat down to process everything, a sultry voice echoed through the hallway outside his room.
"Tatsuya~…"
He froze.
The door creaked open a little, and there she was—his older sister, Aoki Yori.
She was fresh from a bath, skin dewy with steam, and clad only in a loosely tied bathrobe, damp and clinging to her curves. Her long mauve hair, still slightly wet, was tied into a lazy braid draped over one shoulder. The robe hung off her frame carelessly, and for one heart-stopping moment, it slipped just enough for Tatsuya to see… everything.
[Image Here]
He snapped his gaze away instantly, but the image was already burned into his brain like a cursed seal.
Yori yawned, stretching slowly, deliberately, her pale thighs flashing from beneath the folds of her robe. She leaned against the doorframe with a teasing grin on her lips. "Tatsuya… why aren't you at the Academy? Today's the big day, right?" Her voice was like silk wrapping around him. "You'll finally become a man…"
Her eyes gleamed with mischief. There was something almost… eager in her expression. As if she'd been waiting for this day.
Tatsuya's face turned crimson.
'Oh. Right… today's the opening ceremony,' he thought, heart pounding in his chest.
The Opening Ceremony.
It wasn't some boring speech and lectures. No. This was the moment all new adults—eighteen and untouched—officially awakened their chakra.
Right there. In front of the instructors. In front of everyone.
Tatsuya stood up so quickly he almost tripped.
"I—I gotta go!"
He bolted for the door, not even sparing Yori another glance. He didn't trust himself to look. Or think. Or breathe.
Behind him, Yori blinked in surprise. Then smiled to herself. "He's acting so strange today…" she murmured, adjusting her robe absently. "Maybe it's just the emotion."
...
The gates of the Ninja Academy loomed tall and wide, crafted from polished redwood and engraved with swirling chakra motifs. Tatsuya hesitated for a second at the entrance—then stepped forward.
Almost immediately, two shinobi in sleek flak jackets stepped in front of him.
"Name?" the one on the left asked, arms folded.
"Aoki Tatsuya," he replied, trying to keep his voice calm despite the tension in his gut.
The other man raised a brow. "Oh… you're Yori's little brother?"
Tatsuya blinked. "You know her?"
The first man let out a nostalgic exhale, eyes drifting for a second. "Know her? She made me feel an amount of pleasure I didn't think was even possible…"
He said it seriously. No hint of exaggeration. As if recounting a religious experience.
Tatsuya sighed. He wouldn't get used to this world quickly.
"You must be quite talented too, then," the other man said, glancing him up and down with a smirk.
"Yeah…" Tatsuya knew what that meant. In this world, "talented" didn't refer to chakra control or elemental affinity. No, it meant something much simpler.
"I'm… nineteen centimeters," he admitted, almost reluctantly.
"Nineteen? That's…" One of them paused. The average length in this world was around sixteen to seventeen. Nineteen was above average, but not that great. For someone like Yori's brother, they'd expected more.
"…Good," the man finished, a little sheepishly.
Tatsuya sighed again. At least I'm better than average, he thought, before stepping past them into the Academy's wide main square.
It was massive. Far larger and more elaborate than the one from the anime. Stone tiles lined the courtyard, and colorful banners with clan symbols fluttered in the breeze. A grand staircase led up to the Academy building itself, where a row of instructors stood in ceremonial uniform.
He recognized two of them instantly: Iruka Umino and Mizuki.
'Wow… this academy looks way better than the one in the anime…' Tatsuya thought.
Bump!
He staggered slightly as someone collided with him, their shoulder hitting his chest.
"Hey! Look where you're going, idiot!" a sharp voice snapped.
He turned—and immediately froze.
Sakura Haruno.
Pink hair. Emerald eyes. A fiery glare. But that wasn't what caught his attention.
Her chest was noticeably fuller than the Sakura he remembered. It didn't match Hinata's ridiculous curves, but it was still a healthy, confident size. More than that, though… her ass was on another level entirely—firm, round, and bouncing ever so slightly as she turned to storm off.
[Image Here]
Tatsuya gawked.
And so did everyone else.
Men. Women. Even one instructor.
He was hardly the only one ogling her. So why should he pretend otherwise?
He kept watching her go, openly.
Damn. This world really is built different.
Before he could lose himself in thoughts any further, a wave of silence swept across the courtyard like a jutsu.
"Shhh!"
Every head turned.
The Hokage had arrived.
To be continued...
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I am a degenerate... I know this...
This story won't get that much support, I know it... but... for the extreme degenerates like me... I hope you'll follow me on this journey.