Chapter Text
Koichi felt useless, not entirely an idiot, but somewhat stupid. His life had taken a turn that was honestly absurd. At his job, they treated him like trash; he was always the only one who fulfilled his duties while the rest slacked off without shame, chatting about nonsense or disappearing on eternal breaks. And in university, things hadn't gone better: after a failed attempt to invite his friends to his home, they had labeled him a weirdo. He didn't understand why they had focused only on the building where he lived, instead of appreciating his good intentions. If his mother saw how his life was now, she would be disappointed... Koichi sighed as he walked, exhausted after doing extra shifts at work. He was tired, and the worst part was that it was already deep night, with the city streets lit only by flickering streetlights. He finished drinking a soda from a vending machine and tossed it aside, not caring much; he just wanted to get home, turn on his computer, and lose himself in Elden Ring, killing bosses and forgetting the world.
Just as he was a few meters from reaching his building, he accidentally bumped into a young woman. From her uniform, she was surely a teenager, but damn, she was very beautiful: orange brown hair falling, piercing eyes that seemed to hide secrets, and a curvaceous figure that made her school skirt fit provocatively.
Koichi blushed instantly, feeling the heat rise up his neck. "I'm so sorry," he stammered, bowing hastily. "I wasn't watching where I was going."
Kuin, for her part, was about to insult him. She had had a shitty day: she hadn't been able to find any subject to consume the Trigger she offered, and her boss was pressuring her to move the product. But upon seeing Koichi's face—that naive, kind, almost pathetic expression—she knew he would be an easy prey.
She changed her angry scowl to a sweet smile, feigning vulnerability. "No, no problem," she said in a soft voice, blinking as if on the verge of tears. "Actually, I was the clumsy one for not watching where I was going. Lately, my beverage business isn't going well at all... surely everyone in the salon will get angry because I didn't get my share. I'm just a girl trying to earn some extra, you know? Life is so hard..."
Kuin played the victim perfectly, tilting her head and biting her lower lip, letting her eyes moisten a bit. Koichi, accustomed to being kind and even helping anyone who seemed to need it, fell into the trap. "Oh, I'm so sorry," he replied, scratching his nape nervously. "Maybe I could buy one of your drinks? I don't have much, but if it helps..."
Kuin smiled inwardly, but outwardly feigned surprise and gratitude. "Really? You're so kind! Thank you, truly." From her bag, she pulled out a mini vial with a dose of Trigger, a murky liquid that shimmered slightly under the streetlight. Clearly, Koichi had no idea what he would be drinking. "It would be 1,000 yen," she said, extending her hand with an expectant look.
Koichi sighed sadly, pulling out his worn wallet and handing her the money. Kuin gave him the Trigger, and stayed watching Koichi with that fake smile, waiting. The young man thought she surely wanted to see if he liked it, so he opened the tiny vial and drank its contents in one gulp. In a second, the Trigger took effect: Koichi felt himself gradually getting dizzy, his vision blurring, and a strange wave of heat coursing through his body.
"What... what is this...," he murmured, staggering.
Kuin grabbed him by the neck with surprising strength, her fingers sinking into his skin. "Thanks for cooperating, idiot," she hissed, and threw him into the dark alley like a rag.
Koichi fell to the ground, agonizing in pain, gasping as the Trigger transformed his body. Veins bulged on his skin, his skinny figure grew a bit—not to grotesque deformities, but enough for most of his clothes to rip, revealing swollen muscles as if he had ingested steroids in excess.
"Shit, this is disappointing," Kuin muttered, laughing sadistically. "I thought your Quirk would be stronger. A shame..." She spat on Koichi while he still agonized and writhed on the ground, turning around. "I'll argue hard with Number Six for giving me defective Trigger. Maybe what they produce in the United States isn't different from All For One's."
Then she heard a strange noise. She turned... and was slammed to the ground. Koichi pinned her arms.
Kuin struggled to break free, but it was useless. That “idiot’s” strength completely overpowered her. She noticed he was strangely flushed, eyes glassy and drooling. A drop of saliva landed on her face. The scent was thick, animalistic, and... strangely arousing. No, that was impossible.
Before she could command her hive to attack him, Koichi lunged forward and kissed her with desperate violence.
Kuin resisted at first, thrashing, but his saliva slid down her throat. Her body convulsed instantly. An orgasm hit her like lightning, intense and sudden. She felt her skirt soak through; her panties were drenched. She gasped against his mouth, betrayed by her own body.
She looked down and saw the monstrous bulge in Koichi’s torn pants. It was huge, disproportionate, throbbing hard. Before she could react, she felt a hand sliding under her skirt, roughly pushing aside her thong. Koichi’s thick, hot fingers thrust mercilessly into her virgin pussy.
Kuin screamed, half in pain, half in unexpected pleasure. He fingered her furiously, savagely, his digits curling inside her, hitting spots she’d never felt. He kept kissing her relentlessly, his tongue invading her mouth, mixing thick, hot saliva. Kuin writhed beneath him, trying to fight it, but another orgasm crashed over her—much stronger. Her vaginal walls clenched around his fingers, hot squirts soaking his hand and the alley floor. Steam poured from her open mouth, eyes rolling back, lost in lust.
Koichi didn’t stop. He pulled his fingers out and, with a low growl, positioned himself between her thighs. Kuin looked down and, for the first time since possessing this body, felt real fear. Koichi’s cock was grotesquely enormous: thick as her wrist, veiny, the swollen head glistening with precum. Over 30 centimeters of throbbing meat.
Kuin shrieked as he began to push in. The head brutally forced her pussy lips apart, stretching her to the limit. “Stop! Stop, you idiot!” she screamed, but Koichi wasn’t listening; he just growled, eyes bloodshot from the altered Trigger. He thrust deeper, tearing through her hymen in one savage motion. Kuin felt burning pain mixed with overwhelming pleasure as he filled her completely, his cock battering her cervix with every inch.
When he was finally buried to the hilt, Kuin blacked out for a moment. Only pure, animal lust remained. She kissed Koichi desperately, tangling her tongue with his, biting his lips until they bled. Her hips bucked instinctively, craving more.
Koichi began pounding her with uncontrolled violence. Each thrust was deep and brutal, his heavy balls slapping her ass with wet, obscene sounds. Kuin screamed in ecstasy, nails raking his back, leaving red trails. Her breasts bounced under her torn school blouse; Koichi lowered his head and bit a nipple hard, sucking it roughly while continuing to fuck her mercilessly.
Minutes stretched into eternity—or perhaps hours—in that dark alley. Kuin came over and over, each orgasm more intense. Her pussy gushed constantly, forming a puddle beneath them. Suddenly, Koichi flipped her over, putting her on all fours like an animal. He slammed into her from behind, even deeper, hands gripping her hips hard enough to bruise. Kuin moaned like a whore in heat, pushing back to take it all.
He fucked her doggy-style until she came again, squirting hard against his thighs. Then he lifted her against the alley wall, her legs wrapped around his waist, and pounded her standing, their sweaty bodies slapping together with lewd wetness. Kuin bit his neck, licking the salty sweat, completely lost in depravity.
Koichi growled incoherent words, his cock swelling even more inside her. Kuin felt her cervix yielding slightly with every thrust, as if her body was adapting to the monstrosity. Another orgasm ripped through her, eyes rolling back, tongue lolling out, drooling just like him.
Finally, after what felt like an eternity of savage, depraved, limitless sex, Koichi roared and came inside her. Thick, hot ropes flooded her womb, so much it overflowed, dripping down her thighs. Kuin shuddered with one final massive orgasm, her mind blank, nothing but pure pleasure.
The hot, slick tip of that monster pressed against her virgin asshole. Kuin’s eyes snapped open, a flash of genuine fear crossing her face for the first time in ages. “Wait... no, not there...” she tried to say, but the words turned into a moan as Koichi pushed forward.
The thick head forced its way in with cruel slowness. Her tight ring resisted at first, burning, stretching beyond imagination. Kuin screamed, sharp pain slicing through her like a knife. Her legs trembled around him, instinctively trying to pull away, but Koichi held her firmly against the wall—one hand on her nape, the other spreading her cheeks.
But then... the fear vanished.
As if a hot fog flooded her mind again, the pain transformed into something dark, delicious, addictive. Her traitorous body, corrupted by Koichi’s saliva and cum, surrendered completely. Her asshole suddenly relaxed, and Koichi thrust deeper with a guttural growl.
Inch by inch, that impossible cock sank into her ass. Kuin felt every vein, every throb, every pulse as her insides opened for him. Tears rolled down her cheeks, but not from pain—from overwhelming intensity. When Koichi finally bottomed out, his heavy balls pressed against her soaked cheeks, Kuin let out a long, broken, almost animal moan.
Koichi didn’t wait. He started moving immediately, pulling out almost completely before slamming back in to the hilt. Each thrust grew faster, wilder. The sound was filthy: wet skin slapping skin, the squelch of her ass lubricated by the juices constantly dripping from her empty pussy.
Kuin clung to him desperately, trembling legs wrapped around his waist. Her clit rubbed against his pubic bone with every thrust, sending sparks of pleasure that made her convulse. “Yes... fuck, wreck my ass...” she whispered against his neck, biting the salty skin, utterly lost.
Koichi tilted his head and kissed her violently. His tongue invaded her mouth in perfect sync with his cock invading her ass: deep, dominant, merciless. Kuin sucked that tongue greedily, swallowing more thick saliva that kept her drugged, submissive, addicted.
Her hips moved on their own, rocking back to meet every brutal thrust. The lingering pain only heightened the pleasure, turning each thrust into an explosion of forbidden sensations. Her empty, jealous pussy gushed constantly; her thighs shook as another orgasm built deep inside her.
Koichi sped up, pounding her with uncontrolled fury. His hands squeezed her ass cheeks hard enough to leave finger-shaped bruises. Kuin screamed into his mouth as she climaxed: a devastating anal orgasm that made her squirt hard against his abs, hot jets splashing their joined bodies.
But Koichi didn’t stop. He kept fucking her relentlessly, deeper, faster, until her mind shattered once more into pure depraved ecstasy.
Hours later...
Just before dawn broke over the city, Kuin knelt in the filthy alley, lips stretched wide around the monstrous cock of the man who had completely destroyed her hours earlier. Boyfriend? No... she would never fall for someone like him. She was a villain. A parasite. A weapon. And yet, there she was, willingly—eagerly—sucking the thick, veiny shaft that still throbbed with unnatural heat.
Koichi lay semi-conscious against the wall, his torn pants long discarded, his grotesque erection standing proud despite hours of relentless, brutal fucking. Kuin’s jaw ached from his size, but she didn’t stop. She slid her mouth down as far as she could, tongue swirling around the swollen head, tasting the salty mix of dried cum and her own juices coating every inch. Her hands gripped the base—her fingers couldn’t even close around it fully—and stroked it with slow, deliberate motions while she bobbed her head.
She hated how good it felt. She hated how her body responded even now. Her pussy, still swollen and leaking a steady stream of his earlier loads, clenched involuntarily every time his cock pulsed against her tongue. She was soaked again, thighs slick, the puddle beneath her knees growing with every passing minute.
Koichi groaned low, hips twitching. His hand tangled in her hair—not guiding, just resting—as his breathing grew ragged. Kuin felt it coming before it happened: the shaft swelled impossibly thicker in her mouth, veins throbbing against her lips. Then he came.
A torrent of thick, hot cum shot down her throat. Again and again, far more than any human should produce. Kuin swallowed greedily, without hesitation, her throat opening around him as she drank every drop. The taste—musky, irresistible, addictive—sent a lightning bolt straight to her core. Her free hand slid between her legs, fingers plunging into her wet, abused pussy. She fingered herself frantically, curling deep, thumb rubbing her hypersensitive clit.
She came almost instantly, a sharp, shameful orgasm that shook her entire body. Her pussy clenched around her fingers, weakly squirting onto the alley floor as she moaned around Koichi’s still-spurting cock. Cum overflowed from the corners of her mouth, dripping down her chin onto her torn blouse and exposed breasts.
When the final spurt finally ended, Koichi’s hand slipped from her hair. His head lolled to the side, eyes closing as exhaustion finally claimed him. He passed out, chest rising and falling in deep, uneven breaths.
Kuin pulled off his cock with a wet pop, strands of saliva and cum connecting her swollen lips to the glistening tip. She gasped, wiped her mouth with the back of her hand, and staggered to her feet. Her legs shook violently; she felt every muscle in her lower body bruised and overloaded. She stumbled until her back hit the opposite wall, sliding slightly down as the fog of lust finally began to lift.
The clarity that followed was nauseating.
She looked at Koichi’s unconscious body—the monstrous cock still half-hard between his legs, the scratches and bite marks she’d left all over him—and realization hit her like a wave. He did this. His altered Trigger. His saliva. His cum. Whatever mutation it had awakened in him had turned her—Kuin, the untouchable villain—into a drooling, cock-obsessed slut for hours.
Rage flooded her so fiercely she almost screamed. Her stomach churned. She turned and vomited against the wall, retching until only bile remained.
One of her hands elongated grotesquely, her nails extending until they almost resembled sharp blades, shining under the dim dawn light. She would take advantage of Koichi being unconscious to kill him, to get revenge for making her so vulnerable, for fucking her like an animal and making her beg for more.
"I'm going to gut you, idiot... you'll feel my nails tearing your throat while you choke on your own blood," she murmured in a hoarse voice, approaching him with slow steps, her extended hand ready to pierce his exposed neck.
She imagined the warmth of his blood splattering her skin, the gurgling sound of his agony, and for a moment, that aroused her again—a twisted depravity that made her pussy throb. But then, when she was about to sink her claws, something stopped her: a cunning thought crossed her mind. Maybe she would have a golden opportunity to experiment with him in the future. After all, the old man Garaki had said he needed test subjects for his most recent experiments, to create the ultimate life form that would end All Might.
"This imbecile could be perfect... his body resisted the Trigger in an impressive way," Kuin thought, slowly retracting her nails, feeling a tingle of anticipation.
Curious.
Very curious.
Someone who looked so fragile shouldn’t have that kind of resilience. Shouldn’t have turned the Trigger into... whatever this aphrodisiac mutation was. Maybe his body assimilated it perfectly. Maybe he was exactly the kind of anomaly Garaki dreamed of.
She exhaled sharply through her nose, decision made.
For now, she’d keep him close. Study him. Watch how the Trigger evolved inside him. And when the time came... she’d hand him over to the doctor. Or keep him. Whichever proved more useful.
Kuin rummaged through her abandoned bag, pulling out wet wipes and a spare uniform skirt and blouse she always carried. She cleaned herself as best she could, wiping dried cum from her thighs, stomach, and breasts, then changed into the clean clothes. She stuffed the ruined outfit into a trash bag.
She looked back at Koichi. Naked, bruised, covered in their mixed fluids, completely helpless.
With an annoyed sigh, she took out her phone and called an ambulance.
“Yes, hello? I need an ambulance. My… friend was attacked. We were mugged, I think he hit his head… he’s unconscious. No, I’m okay, just shaken. Please hurry.”
She rolled her eyes at the dispatcher’s questions, kicking Koichi lightly in the ribs to confirm he was still breathing. A faint groan escaped him—good, alive.
This was going to be a massive pain in the ass, inventing a believable story. But it would get him to a hospital, keep him alive, and—most importantly—keep him within reach.
As she waited for the sirens in the distance, Kuin crouched beside him, brushing a strand of hair from his forehead with an almost tender gesture she immediately regretted.
“You’re mine now, idiot,” she whispered, voice low and dangerous. “And I’m going to figure out exactly what kind of monster you really are.”