Experiment gone wrong.
"You swear?" Mikasa shot the research captain a glare.
"Yes yes! I promise! If you do this I won't touch Eren for a month!" Hanji whined, eager to get this experiment on the run.
Mikasa knew for sure something weird was gonna happen, her sharp senses were tingling. Nevertheless, for the sake of her oh so precious brother, she was more than willing to take a bullet through that thick skull of hers. Sighing, Mikasa sat on the chair Hanji had instructed her to do so earlier. The mad woman grinned and went to her table only to start mixing stuff up. Stuff that Mikasa did not recognise. Hope for the best, that's what the half oriental could do.
"Done~" Hanji said in a sing song tune as she moves towards Mikasa. "Here... drink this"
Mikasa swore she could see devil ears popping out of Hanji's head along with a pointy tail. She took a deep breath, and gulped down the concentrated liquid... She felt herself slowly feeling more and more faint. Soon enough, Mikasa Ackerman laid on the floor, passed out. Hanji continued grinning sheepishly while carrying the blacked out woman to the infirmary.
After what seemed to be like days, but only an hour, Mikasa's eye lid twitched, then blinked as she began to awake. She felt nothing out of the ordinary really, only a little heavier, not sure if that's the right way to put it. She flinched slightly upon hearing a loud voice.
"Hanji! What the hell were you thinking?! No... Were you even thinking at all?!"
Mikasa recognise that hoarse voice anywhere... The man she hated, the Lance Corporal, Humanity's Strongest. She was still feeling faint, but could listen to the conversation clearly.
"C'mon Rivaille~~~ she agreed!" Hanji pouted, although Mikasa couldn't see it.
"That does not give YOU the RIGHT to CHANGE ACKERMAN INTO A FUCKING MALE!"
Mikasa blinked. Once. Twice. Thrice. Did she hear that correctly? Then she shot up and look down on her body... Apparently it wasn't convincing enough so she rushed towards the only mirror in the room. Her calm eyes widen due to shock or horror, no one knows. As of right now... She's a... goddamn man.
"I see you're awake..." the shorty said, making his presence visible.
"Mikasa~!" Hanji squealed but stopped when Mikasa glared at her.
"What the hell did you do to me?!" Mikasa yelled, voice being way deeper than it originally was, "Turn me back. Now. " Mikasa demanded, venom dropping after every word.
"I-I can't! It'll wear off after a few hours..." Hanji squeaked, hiding behind the Corporal.
Mikasa huffed and went out of the infirmary, with the Corporal trailing behind her.
"Ackerman... Do you still wish to continue your training session with me as usual?"
After the unfortunate incident where Rivaille's team were... wiped out, Mikasa was recruited by the short man himself. Everyday they had started to train together. Although it meant less time with Eren, Mikasa reluctantly agreed as this is the perfect way to get stronger and protect Eren. Mikasa nodded. Realising the fact that she currently bears the strength and body of a man's. It may be... cheating, but she never did get to have her revenge on him from when he beat the shit out of Eren.
The two soldiers headed to their usual area and started a hand-in-hand combat. True, Mikasa's usual inhuman strength had increased tenfold, but the body remains unfamiliar to her, making her actions a little slower. She had managed to land a few more hits on the Corporal than usual, ones with more impact. She smirked, it was indeed payback. Maybe just for now, she would forgive Hanji for this. Just as she was about to land another blow, Rivaille reappeared behind her. He pushed her towards a tree nearby and pin her there, although it was harder since now she was in a man's body.
"You think you can beat me with that body Ackerman? Well think again-"
With just a push, Mikasa managed to cut off Rivaille's words and left him on the ground, dirt rubbing off his clothes to his dismay. Dammit, she could do better as a damn male, can't she? Rivaille quickly got up upon reflexes just in time before Mikasa was about to lay another punch. Hearing her curse, the Coporal prepared himself for another showdown, no way would such a lame excuse like Mikasa turning into a man bring him, humanity's strongest, down.
The fight went on about an hour or two until Mikasa was out of breath, Rivaille no better than that either. Mustering all the strength she has left, Mikasa grabbed onto the Corporal's cravat and slam him against a tree... Much like what he did to her just now. Rivaille cursed under his breath, leaning into Mikasa, too closely for the oriental's liking. And in just a flash, the tables turned, no longer was the corporal pinned onto a tree by his recruit, it was indeed the exact opposite. Mikasa, feeling unsatisfied, squirmed and struggle, but to no avail, the man in front of her wouldn't budge. And it certainly did not help when she suddenly felt weak. As much as the said girl- man, wanted to make her eyes stay open, they couldn't.
Rivaille, on the other hand, was well aware of the situation. He could in fact tell that Mikasa was feeling weak right now. But why? He did not know, although it wasn't long before he found out. Slowly, almost as if it was magic, Mikasa's body changed. Her chest was suddenly growing, the shirt she wore started to expand in that certain area. While that was going on, Mikasa's hair slowly grew out in length, back to her usual style. Her waist became as slim as before, in fact, the shirt that she wore, which fitted her man-body before, was now slightly too big for her. Soon enough, Mikasa opened her eyes, still a little fuzzy.
"Cor...poral...?" Mikasa said softly, Rivaille taking notice on how much he had missed her soft sweet voice unlike the deep one.
"Mi- Ackerman, are you feeling alright now?" Rivaille shook off his thoughts and asked the girl, forgetting that he was still pinning her.
"I'm fine..." Mikasa said, mind becoming clearer and realising the fact that she turned to normal.
Mikasa wanted to move her hands to massage her head, but too realized that she was still pinned. Flickering her gaze, she was the shorty staring at her weirdly. Not so much as weird but... Abnormal or unusual.
"Corpora-"
The next thing Rivaille did was shocking to Mikasa, more shocking to when she realized that she had been changed into a man. Rivaille, lance corporal, her superior, humanity's strongest... Kissing her! Mikasa instantly reacted by trying to move her hands, but Rivaille was too strong, plus the fact that her strength had gone back to usual since she turned back, she just couldn't get out off the corporal's grip.
When he needed air, Rivaille parted his lips with Mikasa's. Seeing her shocked expression pleasured him oh so well. He smirked, eyes still on his recruit.
"Tomorrow morning Mikasa, tomorrow morning I'll train with you again."
With that, he left, making the stunned Mikasa freeze in her spot. While his mind wandered to what would he do if Hanji's experiment last forever and Mikasa would stay a guy. Well, that's only for him to know.
The next morning...
"Where is the corporal, dammit." Mikasa said. It was already time for their training and the said man still hadn't show up.
"Ackerman. " a... Soft, high-pitch... Simply, a girlish, voice called out.
Mikasa spinned her head just to see a female that looks just like the corpo- Bingo. Suppressing her laugh and amusement, Mikasa looked over at Rivaille.
"Did Hanji turned you too... Ma'am?"
Mikasa mocked.
"DAMMIT ACKERMAN. SHUT THE FUCK UP."