One morning at Ashford Academy...
Kallen Stadtfeld was starting to get a bit worried. None of her panties seemed to fit her as well as they used to. No matter how hard she tugged on them, even to the point where the fabric started to tear, her underwear hardly ever made it past her mid-thigh. The largest pair she had felt more like a thong as it clung tightly to her creamy-white bottom, burying itself deep into the thin crevasse betwixt her butt-cheeks. It frustrated the redhead as she attempted to pull it out, so in the end she had little choice but to remove those panties altogether. With a grunt she tossed them carelessly over her shoulder and onto the ever-growing pile of underwear behind her. She certainly couldn't so much as leave her room without underwear, but her choices of lingerie were dropping fast. Oddly enough, it only seemed like her panties were giving her trouble; while her breasts were large, she was still able to obtain comfortable cup sizes for them.
Sighing, the young woman turned slightly sideways and stared at her reflection in her closet mirror. Her mouth fell agape in utter shock; her ass was huge. Well, she had always been aware that she was a bit more 'gifted' in the booty department than most girls her age and weight, but she couldn't deny now that her bum had seriously ballooned since the last time she seriously looked at it. It was even bigger than her breasts!
The two bloated spheres of skin and fat stuck out a foot and a half behind her, like a spare shelf. She slowly brought a reluctant hand upon her left cheek and squeezed it. The color drained for her face when she realized bulging flesh was peeking out from the spaces between her lithe fingers. She ran another hand over the vast expanse of her full ass and palpated the soft, pillowy curve it formed. There wasn't a single dimple to be found, and her thighs were also wider to accommodate her butt. After this quick examination of her posterior, she released it from her grip, prompting the cheeks to flap with wild abandon. Her butt eventually ceased its jiggling motions about ten seconds later.
Kallen was less distressed than when she first made the discovery of her enlarged bum, but she still could not comprehend what could have caused this to happen. This did help explain a few past occurrences in her life to her however. 'Is this the reason why so many guys have been staring at me lately? Why those bitches in the tennis club were laughing? Is this why my mom was so anxious about me getting more exercise? It's all because my butt got big and I never even noticed? What the hell! They should have just told me in the first place...but how did I end up like this?'
Kallen sat herself down onto the edge of her bed, her massive buttocks trembling all the while, and she thought back over the previous couple of months. A while back, she had been placed on standby under Zero's orders until the point where her abilities as a mecha pilot would be needed again by the rebellion. So far she hadn't received a single mission since then, and she didn't even bother exercising. She spent the majority of her time going to classes, sleeping in, and eating lots and lots of pizza with C.C..
Suddenly, it came to her. 'It was C.C. and all of that pizza! I need to go talk to her right now and give her a piece of my mind!'
Quickly throwing on a pair of sweatpants and a t-shirt, the big-bottom girl darted out of her room and down the hall. She paid no mind to the uncontrollable trembling of her ass as she ran or to the many passerby who stopped and stared in either amazement or disgust. It was all terribly embarrassing, but right now it was the least of her worries. While she knew deep down it was her own fault for eating so much pizza, she couldn't help but want to place all the blame on C.C., since it was her who ordered the food in the first place. Kallen wanted something proper to let loose her rage on, and because C.C. was an immortal witch, she would have to do.
Kallen kicked open C.C.'s door, fully prepared to scream at the lime-haired woman, but instead she saw a pair of massive ass-cheeks contained within a white strait-jacket wiggling in her face. She looked over the bulbous booty to see poor C.C. struggling to stand up despite it. Her butt was so big it actually prevented her from being able to move properly. The girl was actually weeping into her cleavage, which had also swollen out.
"I...I can't move...all that pizza made me so fat..." C.C. whimpered.
"Uh...I'll come back later..." Kallen walked out and closed the door behind her.