The high-pitched drone of the final bell echoed through the sterile corridors of Sakura High. Aiko Kaneshiro leaned her cheek against the classroom window, her breath fogging up the glass. Down below, the soccer team practiced under a gold-tinted sky, shouting, laughing—living.
She was not like them.
Top of her class, invisible in the halls, she was a girl whose name teachers praised and classmates forgot. Her world had always been neatly color-coded: black and white, right and wrong, virgin and... everything else.
Until today.
The lightning struck just as she stepped off the curb.
A searing pain. An explosion of light.
Then—nothing.
When Aiko opened her eyes, she expected a hospital ceiling. Instead, a sky of molten lavender stretched above her, stars glittering like broken glass. She sat up slowly, blinking against the brightness. Her school uniform was torn, soaked with dew. The grass beneath her shimmered—was it glowing?
She wasn't on Earth anymore.
Her breath caught as she heard movement. Armor clinked. Footsteps approached. A group of tall, muscular men emerged from the trees. And not just any men—barbarically handsome, dressed in fur and steel, eyes glowing with strange hues.
One of them stepped forward, tilting his head.
"A female…?" he murmured, voice thick with disbelief. "The prophecy was true."
Aiko backed away. "Where the hell am I?!"
Another man crouched, looking at her like a wild animal discovering fire. "You smell fertile."
"What the f—" Aiko's voice cracked. "Don't come any closer!"
Their eyes weren't just glowing. They were hungry.
The tallest of them, bearing a sword longer than she was tall, extended a hand. "Don't be afraid. You are the key to saving Virelia."
"Saving—what?"
"You are the Firstborn," he said reverently. "The only woman in a world of men. A gift from the Goddess of Lust."
Aiko blinked, her mind short-circuiting.
Before she could respond, a chime rang through her skull.
---
[ SYSTEM NOTICE – INITIATING HOST INTEGRATION ]
User ID: Aiko Kaneshiro
Race: Female (Mythic-Class)
World: Virelia
Status: Level 1 Virgin
Class: Erotic Heroine
Title Unlocked: Firstborn – The only known female in the realm. Your existence defies nature. Men will covet you. The world will bend for you.
Main Quest:
Defeat the Demon King through Erotic Submission (0/1)
Return to your original world (LOCKED)
Mechanic Unlocked – Breedbound Sync
Every time you sexually dominate a male, you gain one of their skills or traits.
Sync Rate: Based on intensity, mutual satisfaction, and risk.
Side Effect: Extreme arousal, addiction potential, emotional imprinting.
WARNING: Your body will undergo changes to adapt to the Breedbound System. You may develop unexpected desires, physical sensitivity, or supernatural libido. Proceed with caution.
---
Aiko screamed.
One of the men rushed forward, trying to catch her, but she darted into the woods.
Branches lashed at her arms. Her breath came in gasps. She didn't stop until she reached a clearing—and ran straight into someone.
She stumbled back. He caught her.
Unlike the others, this man wore no armor. Just a dark tunic, soaked with sweat, revealing a lean but powerful frame. His eyes were obsidian, deep and unreadable.
"Did they touch you?" he asked coldly.
"No," she snapped, stepping back. "Who the hell are you people?!"
He studied her like one might a dagger they didn't trust. "You'll attract every man within a hundred leagues. You shouldn't be running through the woods like that. It's… dangerous."
"You think I want this?" she yelled. "A world full of horny guys and a system that wants me to what—fuck them all to death?!"
The man's jaw tightened. "That's a crude simplification, but… accurate."
She hated how calm he was.
"Take me home," she demanded.
"You can't."
"I'm not a toy."
"No," he agreed. "You're a weapon. A sacred one."
Aiko opened her mouth to curse him out, but he stepped closer—and something shifted in the air. Her breath caught.
Heat bloomed low in her belly. Her knees trembled.
"What… is this?" she whispered.
"The system's recognizing your first potential sync partner," he said, voice like velvet wrapped in steel. "It wants you to taste power."
"No," she said, but her voice quivered.
He didn't touch her.
He didn't need to.
"I'll wait until you beg," he said softly.
She hated how much that turned her on.
He turned and vanished into the woods.
Aiko dropped to her knees, panting.
---
[ SYSTEM UPDATE – SYNC COMPATIBLE TARGET IDENTIFIED ]
Name: Kael Ravaryn
Class: Shadowblade
Skill Available Upon Sync: Phantom Step (grants invisibility for 3 seconds)
Emotional Compatibility: Low
Dominance Resistance: High
Warning: This target may attempt to reverse-sync. Exercise caution.
---
"Reverse-sync?!" she choked. "What does that even mean?!"
But a darker voice inside her whispered: You liked that, didn't you?
Aiko curled up on the grass, furious at herself.
This world was insane. She was a virgin. An honor student. A girl who'd never even kissed a boy.
And now she was supposed to become some kind of erotic monster?
The leaves rustled. She sat up, heart thundering.
Kael reappeared, tossing a cloak at her.
"You're cold," he said.
She caught it. "Why do you care?"
"I don't," he said. "But I can't let you die. Yet."
"Gee, thanks."
He turned again. "Come with me. You'll need shelter."
"And if I don't?"
"You'll last a day. Two, if you're lucky. Then the system will trigger Heat Mode. You won't be able to resist anything."
Aiko stood slowly, fists clenched. "Then I'll come. But I'm not your toy."
Kael gave her a faint smile. "You keep saying that. Let's see how long you believe it."
As they disappeared into the trees, the stars overhead shimmered—watching, waiting.
The Breedbound Heroine had arrived.
And her legend was just beginning.