This fanfiction is a novelization of the work done by Himura Kiseki on Getsuyoubi no Tawawa.
She was there. Onii-san quickly recognized Ai-chan at the end of the platform waiting for him. He could have recognised her amongst everyone in the train station. Yet, something about her was different from usual. It was not about her beauty or her curvaceous figure, but she was differently beautiful. Before he could tell what, he managed to get to the end of the platform and greeted her :
- Good Morning, Ai-c…
She turned around, making her enormous chest jiggle heavily. He then remembered that this alias had no use anymore. From their last encounter, she made it clear that she had... somewhat improved.
- Hum… no, I mean… Jay-chan!
The busty schoolgirl looked at him and her face glowed.
- Good morning, Onii-san! Well, you know, "Ai-chan" is fine!
- But, didn't you say that you... hum, that your... I-I mean th-that you..
Onii-san was already starting to stutter, unable to pronounce the words he wanted to say. Ai-chan's look changed to a more teasing one. Her voice too, took a deeper, strange coyly tone :
- Well, changing my name every time would be a hassle, right?
Onii-san froze with an incredulous expression. What was that supposed to mean exactly? Hasn't she already graduated from an I-cup to a J-cup last Monday ? Was she really going for a K-cup? Is it even possible? She was surely making fun of him. A J-cup was already a monstrously huge size that he initially thought was impossible to reach. Just walking on its way to the station showed him that mature Japanese women rarely exceeded a C-cup level. And this little Ai-chan was seven cups ahead of them. No, she was surely joking. She must be. And yet, he could help but to notice it : her chest was indeed slightly bigger. But that was surely because she was wearing a bra that was matching her size. Her breasts were not really overflowing like last week, but they were looking slightly bigger, helped by the nice support of what he assumed was a brand new J-cup bra.
He then considered two things. First, she was young, probably 17 years old. Maybe, her puberty was not finished yet. It was totally possible that the few remaining hormones left were planning on making her grow a bit more. And secondly, a pure jewel like her could not possibly be a liar. He felt her two mountains against him on two different occasions, there was no doubt she was huge.
- O-okay, I'll keep calling you "Ai-chan" from now on then...
That's when he finally found what changed in her appearance. It was just above her incredible area.
- Oh, what? A ribbon? He asked.
Instead of her regular tie, a big black ribbon was laying on top of her bust.
- Hehe, at our school, girls have a lot of options, she giggled.
- I see...
She did not reply but was acting as she wanted to. The young teenager remained silent, looking awkwardly here and there. She was shifting her weight from one foot to the other, playing with a strand of her hair, looking absent-minded. This attitude made her purity and innocence glow even more through her. That's when Onii-san knew she was waiting awkwardly for him to do a compliment. How dumb could he be ?
- It looks great on you! You look really cute! He yelled a bit too loud. It gives me a lot of energy, I can work for another week, thank you!
Ai-chan's smile started to make her face glow with joy.
- Hehe, you're welcome I guess, she giggled.
She pointed with her finger to the ribbon above her massive assets making Onii-san look down.
- Then, which do you prefer? She asked, referring to a tie.
- That's a hard question.
Both were hard to be indifferent with honestly. He always found ties to be more formal while ribbons were more feminine. For her condition, the ribbon was looking good on her chest, underlining her assets. He then realized that he never saw her with her blazer closed, which was not really appropriate to a high-school's policy.
- How about you button your jacket first?
- Eeeeeh, why ? It's so hot already and I don't really like it, she replied with a bored attitude.
She shook her jacket in disdain, making her mountains bounce a bit. Onii-san looked down and immediately found a difference with the ribbon. Even though the busty girl had changed her bra to fit her enormous breasts, her uniform's shirt remained the same. It was quite stretched to hold her two tremendous treasures and there were already gaps in between the buttons, accentuated by her slight movements. Without her necktie, one could easily see these captivating slight gaps between her buttons.
- "Why"? Well… it's because… uh… said Onii-san, mesmerized.
He didn't even know what they were talking about. Was it the jacket ? Ai-chan looked at him and he was almost certain to see a faint smirk appear at the tip of her mouth.
- Well…if you want it buttoned up…, she said with a seductive tone in her voice.
She took a step towards him.
- …then please be my guest, she continued.
In the brief moment during which Onii-san could simply stutter a simple "Huh?", the young teenager closed her eyes and with a smile, straightened her back and clawed her hands behind her, pushing her elbows back. She did not appear that much taller given her small height but that was not where the real growth happened. Her already huge chest sticked out more and more, reaching a colossal size. The gaps between the buttons of her shirt increasingly widened, straining the fabric to its limit. By this single innocent move, Ai-chan was showing all of her might and uniqueness, exposing the full potential of her J-cup bosom. Right now, there is no doubt about it: it will be impossible to button her jacket. Onii-san's remained gaping : he never saw a chest being this massive.
- Come on try it, I'll leave it to you, coyly said Ai-chan, her eyes still closed as if she did not want to acknowledge the heavily erotic situation even though her smirk blatantly betrayed her enjoyment.
Onii-san started to sweat rapidly. On one hand, the situation was more than risky. After all, despite her incredible look, Ai-chan was a schoolgirl that could not even reach 160 cm while he was a grown man, working in a company and topping her with more than 20 cm. If he were to get caught by someone else approaching his hands in a lewd manner, it would be impossible to explain. And yet, on the other hand, Ai-chan was standing in front of him, her massive chest all puffed up and asking him to contain its glorious size. The more he was looking at them, the more he couldn't even believe in its tremendous volume. Slowly, he hesitantly approached his hands closer to her two massive assets.
- Hum, then...well…O-ok, he stuttered after looking one more time around them.
Unsure of what he was doing, he grabbed the two sides of her jacket. The inside of it was delightfully warm, heated by her body's flesh. He was so close to her that he could see the young adolescent's mountains rising up and down during her breathing, much to the demise of her shirt. Her buttons were desperately holding their positions against their powerful crushing enemies. Onii-san thought he could watch this fantastic miracle for decades. As he was taking a good grasp on the sides of her jacket, he started to pull them closer together, asking himself what on Earth she was making him do. Careful to stay a few millimeters away from her bust, he pulled on her jacket and tried to button it and that's when it hit him. The two sides of her jacket were off together by a good 10 centimeters. For it to work, he had to be in contact with her breasts. And she knew it.
Ai-chan slowly opened her eyes, her eyelids opened half-way in a smug attitude, looking down on the two hands that were taking a better hold on her jacket, hoping to make a second attempt. A prideful smirk appeared innocently of her mouth as Onii-san, sweating profusely, pulled once again her jacket. He pulled with much more force than before, flattening her jacket against her back. Trying to win the slightest advantage of clothes he could possibly obtain, he tried to pull them against her breasts, for the first time touching them lightly, following the line of her curves. They were gloriously soft, softer than everything he could have imagined. They were just like when he first met her and he tried his best to forget about the fact that she had just graduated from an I-cup bra. He firmly followed her bosom circumference where they mere at their most powerful size. He was so close to her flesh, that he could feel the texture of her mighty new bra under her shirt. The doubts he had before vanished : she was indeed a J-cup and from what he felt, a big one. Ai-chan remained attentive until he reached the end of her jacket's fabric. He was missing five more centimeters. Onii-san let out a slight sigh of panic. Ai-chan eyelids lowered a bit and her smirk grew a bit larger, blatantly prouder than before.
But what was more striking was her silence. She was enjoying every bit of his struggle, toying with him. Her silence was only magnified by her smirk: she was sure that he could not defeat her whopping assets but was waiting for more, wondering what he could desperately try just to button her simple jacket. Onii-san stood up for his third chance and pulled stronger than before. Her two mountains were already tightly pressed against each other because of her bra but he made them squeeze harder for it to yet it seemed that he was so far away from succeeding. Still pulling harder and harder, he indirectly felt her terrible forces fighting back stronger and stronger against him. Her breasts were crushing against each other,swallowing the teenager's shirt in her cleavage, revealing her canyon by this single act.
As Onii-san was winning some milliliters, managing to get closer and closer and all of sudden…
- Mmh~
It was a foul play. It started with a slight sigh that Onii-san could not fake to ignore. Not only was she enjoying the situation but why did she have to moan softly as he was squeezing her breasts tighter and tighter ?
- C-ca-can y-you s-s-stop mak-ing w-weird no-noises? he stuttered, troubled by her game.
But it was no use. The tighter he was squeezing her mountains, the more aroused her sighs became.
- M-mmh~
But he was close, the two sides of her jacket finally met each other but he had to button it. Pulling as hard as he could, his hands began to shake because of the pressure. He felt the fabric of her jacket already stretched to its maximum but he had no other choice but to ask for more. Trying not to focus on what was going on inside of his friend's shirt, he tried to slip the button inside the hole. His fingers were shaking more and more as they had to hold all of his progress. Ai-chan moaned again softly, visibly enjoying the situation. After this task that seemed to go on forever, he finally managed to slip the button in its hole.
Both of them sighed, Onii-san in relief but he was not so sure about the meaning of hers. He stepped back, quite proud of his well-deserved winning on the defiant teenager. He looked at her with a triumphant expression : he had defeated her evil plan of playing with him. And that's when he knew that there was no way he could have won from the start. His smile vanished in an instant by the sight he had in front of him. Her blazer was stretched to its utmost maximum and the button he was working on was already on the verge of popping, unable to contain her colossal assets. Large creases appeared everywhere around her chest, underlining the massive amount of flesh she was bearing. Under the blazer, her shirt was deeply swallowed by her cleavage to the point where almost all of her front buttons were invisible, sunk in her canyon. The bottom of her ribbon was also slightly engulfed in her assets. But the most unsettling thing was her look. The young teenager was now directly gazing into his eyes with a defiant and proud look. Her eyes were half-closed and her grin grew wider as she was seeing his disbelief. Usually, such a smug attitude would have been impolite but seeing this young woman showing such self-confidence on her imposing feminine traits was unsettling. He then realized something : Ai-chan was not breathing normally. She was instead taking small gulps of air as if her normal breathing would pop her blazer's buttons. Without interrupting her gaze, she took a slightly deeper breath and Onii-san's look down at her chest. Her button was about to pop, deforming the shape of the hole it had been slipped in. She was simply too big and it was clear that this button wouldn't last a few minutes under such a colossal pressure. The next small variation would be fatal for all Onii-san's work.
- I-is it too tight? He stuttered.
Ai-chan's eyebrows raised a little bit, amused by the question.
- Yeah, a little bit, she obviously lied.
- Bu-but ca-can't you ask for a blazer... in a la-larger size?
- Actually, it would be too large for me, this one is the only one that fits me, she answered nonchalantly. Well, for the most part, she added ironically breathing out, underlining her condition.
A short silence followed. It was unsettling how she was not directly talking about her breasts, letting him the responsibility (and therefore the fault) of talking about it. The silence between them drew him to a new discovery. Her small breathing showed how much Ai-chan was struggling to not let her chest tear up her blazer. Each inhalation was shortened, just enough for her to gulp her down the minimum air she needed while each exhalation was followed by a sigh or a moan of relief. In between the two, Onii-san was almost certain he could hear the sound of the fabric stretching. It was impressive, even admirable, how she knew the exact point of no-return of her clothes.
- I…hum… maybe y-you can keep it… o-oopened then, stuttered Onii-san
Ai-chan's gaze and grin looked defiant as ever. She had won.
- Go ahead then, she simply replied
Onii-san that had just managed to relieve a bit was now sweating again. He was not really ready to jump in an another trap of her. Her eyes downed again on her tremendous assets as Onii-san's hands were approaching them once more. He tried to pinch the button out of its hole but all the work he managed to do earlier on was facing him now, greatly helped by the pressure Ai-chan's body was exerting on it. For several seconds he tried to push it back but the hole that was once round had taken a thin long shape making it impossible to pass the button through it. Ai-chan sighed in amusement. Onii-san knew that there was only one thing to do, something he has done before but had to do it : touching her breasts.
The only way was to push the button in her mountains' flesh in order to relieve just a small amount of pressure. Onii-san gulped down in discomfort, took the right side of the blazer with his left hand and the button with his right one and pushed them slightly into her giant mountains. The sensation was beyond anything he imagined. They were perfect in every aspect. First, the softness was incredible to the touch, a real symbol of the pride of her youth. Yet, the firmness striked back with the pressure of them squeezed against each other. Then, the warmth of her flesh hit him as they were welcoming his hands in their lair. And finally, the movement. He could feel how much her flesh was huge against her fingers as she was breathing. Right now, two feelings were battling in his mind. On one hand, he was absolutely focused on his mission to defeat this all-powerful body of hers. And on the other hand, he wanted to surrender and maybe, just grab and squeeze between his fingers her unfathomable assets. He refused to look directly at Ai-chan but he could see in his peripheral vision this same outrageous smirk.
Yet, the button was still blocked. He pushed a little deeper into her mountains and she moaned discreetly, much to the despair of Onii-san. Her chest was now overflowing over and under his hands in bulges contained by her clothes. Each of her assets were easily three times bigger than what his hands could hold. Onii-san was now sure of it: there was no way any uniform that wasn't tailor-made would be able to fit her glorious body. Most of her body had an XS size, but this place was surely XXXL. Lost in his thoughts, he kept trying to unbutton her. And after several seconds of him pushing in, the button managed to slip inside the hole. The pressure that was built for minutes now exploded. Her chest, finally free of what was restraining it, bounced heavily onwards, pushing Onii-san's hands away. Both sides of the blazer opened so fast that they slipped violently out of his hands. However, her shirt remained for the most part deeply squeezed in her cleavage. To top it all, Ai-chan let out a deep sigh of relief as her breasts were still jiggling.
- Pheew, finally ! she said with a joyful smile.
But Onii-san kept looking at her huge chest, his hands still on her jacket. Absentmindendly, he slowly started to undress her shoulder before Ai-chan called him with a chuckle :
- Onii-san ?
- S-so-sorry, he replied, lowering his hands.
Ai-chan took her jacket and put it back up. She took the collar of her shirt and pulled it to drag her cloth out of her canyon back to its original position.
- Oh, for what? There is no need to.
She took a part of her blazer and searched for the button. Both of them looked at it. The pressure had almost made him pop, leaving it hanging by a 2 to 3 cm long thread. Onii-san could not stop himself imagining building a memorial for this brave button, just like a soldier would have had one. Private Button held its ground until the very end, keeping the most dangerous soft weapons in the world contained to the price of its life.
- Oh no! said Ai-chan sadly (even though Onii-san could not believe she had no idea of what she was doing). I have to knit it again!
- Won't you give it to me? boldly said Onii-san.
Ai-chan laughed joyfully, amused while he detached the button of its remaining strings.
- Ah, no sorry, these are expensive and my school property. Don't worry, you'll get yours. Besides...
Before Onii-san could tell anything, she started to take a deep inspiration through her nose, her mouth still smiling. While Onii-san tried to keep an eye contact with her gaze, he could only notice her chest area grow more and more, as air was filling her lungs. Her breasts grew more and more, reaching an immense size. Her gigantic chest already exceeded her previous size and yet it kept getting bigger and bigger. The gaps in between her shirt buttons grew wider and wider, showing holes where no lights could reach until the shirts buttons were threatening to pop too. Onii-san understood with horror : she had not shown her full potential during his trial. There was no way her blazer could have held such a whopping amount. The power of her J-cup breasts were just in front of him, outsizing the volume of two watermelons. She held her breath for a while and finally exhaled with a sigh, her eyes closed. She opened them again :
- It's not like it is difficult for me to create new good luck charms. she said with a smile.
- R-r-r-right, he said, stuttering more than ever.
Ai-chan laughed, making her chest jiggle.
- You should see your face!
Onii-san's face reddened. She was playing with him, humiliating him but he was enjoying it too. What was tormenting him is that he knew she had other tricks up her sleeves. He perfectly knew that she could have popped her buttons with ease as even then, he felt she did not breathe into her maximum capacity. As he was thinking about her power, she passed her right hand inside her collar to reach her bra strap and pulled on it. He saw her monstrous left breast lifted and then bouncing heavily back in position. The weight of it seemed beyond reason.
- Sorry she giggled in a smile while adjusting her right breast in the same position as her left one.
Onii-san thought that this whole scenario would certainly have created havoc in her bra. After all, her breasts were squeezed all together for quite some time and he was sure that they had overflowed from their prison.
- You know what, here's your week's lucky charm she said while handing him over the small button from her blazer. I think you really earned it after all.
Ai-chan winked and giggled as she gave Onii-san his second button who was already thinking about how a new collection could be started. A collection made by the monstrously big chest of a teenager.
Back to the initial question, even though Ai-chan arranged her shirt, the gaps in between her buttons was still visible.
- Hum… I-I think I prefer the tie, said Onii-san
- So you like that one more, uh?
- Yeah, we could leave it at that.
She stopped and asked with an innocent interrogating look :
- Do you like how it waves around?
Onii-san sighed internally. She was probably referring to the fact that her chest was so large that the tie was usually left hanging in the air. He couldn't think there was probably anything sexier. Knowing the answer by the look on Onii-san's face, Ai-chan decided to make fun of him even more.
- Well, they do say that men like things that bounce around a lot, she said with a big, large smile.
While making her ambiguous statement, she softly slammed her foot to the ground, making her giant bosom jiggle heavily in her shirt. Onii-san did his best not to look at her most feminine zone while she continued with a big smile :
- You know like earrings!
- A-ah! Yeah! replied Onii-san with a nervous laugh. She had tricked him once more.
Ai-chan looked at him and he could definitely tell in her eyes that she had one more thing to test him with one second before she said :
- Oh I know ! while diving a hand inside her bag, I actually brought a necktie!
Onii-san sighed joyfully at the idea of another tease.
- Here you go ! said Ai-chan with a smile, handing him her necktie while her other hand unclipped her ribbon. Finally cleared of any piece of clothes, Onii-san could see how stretched her shirt was. The gaps in between her buttons were larger the closer they were to the summit of her breasts. Here at the point where they were the biggest, big openings would have revealed something beautiful if they weren't subtly hidden in the dark. This region of her bust applied such terrible force on her uniform shirt that it was full of horizontal creases while buttons were buried in their holes. Even though the recent events let no place for doubt, seeing her challenging this much a standardized cloth made her shine even more, considering the fact that she was just breathing normally.
- I-isn't it quicker if you do it yourself? stuttered Onii-san while passing the necktie in her collar.
- I'll tie yours for next time she said, her eyes closed and arms in the back.
Having his hands so close again to her magnificent chest distracted him a lot. Several times his hand brushed her soft chest and Onii-san panicked a few times, even though Ai-chan did not seem to care this much.
- You're quite clumsy, aren't you, Onii-san? she chuckled.
- I-it's my first time do-doing it for someone else!
Ai-chan opened her eyes with the same smug look as before.
- Sure, she said.
Onii-san finally tied her necktie in a slow movement from the top of her bosom, following the curvature of her large chest to her neck. Doing so, he wiped off the few droplets of sweat on his forehead. Ai-chan took the tie and passed it in front of her buttons. Her chest was so enormous that almost half of her necktie hung in the air from her bosom.
- Thanks, she simply replied.
The look on his face said it all. Onii-san was looking at her with glee, visibly joyful to have seen her. With this second meeting after the accident, she definitely knew what to do to make him happy. After having tried so many approaches, she finally understood that he had quite a big interest in large chests. And she was more than happy to use her monstrous assets to help him.