Snow was falling all around the city today as a chilly wind was slowly blowing above the train station. Lost in the crowd, the young and busty Ai-chan ran down the stairs with the other commuters. Thanks to the snowy weather in the last days of December, she had changed her outfit for a nice brown pea coat. Even though it helped hide her imposing chest, even the pea coat could not fully suppress the sheer volume of her enormous assets. The stressed wooden buttons were good indicators of how this short girl was so unfairly gifted. But the best element had to come to suppressing the usual heavy bouncing and just for that, Ai-chan was quite happy with it. The small teenager got quickly sunken in the middle of the crowd thanks to her short height. But fortunately, she was looking for someone very tall.

- Fuaaa ! It's even more crowded than usual! she happily said to Onii-san after having wriggled her way through.

The tall salary-man jumped up in surprise and gave her a smile back while his eyes went down, following the magnificent curves of her heavenly body, barely hidden by her pea coat. He was prompt to notice she was wearing a pretty beige sweater under it.

- Yeah the schedule is disrupted because of the snow. A lot of trains are not even running.

- Is that so ? she replied while standing closely next to him.

They looked side by side at the passers-by. Both their gazes stopped on a couple sharing a coffee from the vending machine. Ai-chan instantly recognised the lady the baking company had contacted to arrange their waitress uniforms. What a coincidence again. That young lady did a much better job at hiding her assets than her, a feat of experience without a doubt. But to be fair, it was not like Ai-chan was really trying to during Mondays. The lady and her male friend were discussing the other train alternatives and they were looking at each other quite passionately. Ai-chan could not help but to notice that it was just like Onii-san looked at her sometimes.

- That reminds me, it was Christmas last weekend, he said.

- Yeah, it was, she replied, her eyes sparkling with a dreamy stare.

Both of them sighed. These two people must have been to a fancy restaurant. But other than that, who knows what they did after ? After all, they were grown-ups. Even though they silently looked at them, both Ai-chan and Onii-san thought about the same thing.

- Did you do anything special ? asked Onii-san.

Ai-chan put her bag in front of her and Onii-san could see from the corner of his eyes the two massive bulges of her coat betraying the size of her breasts getting squeezed gently against each other. He didn't know why or how to explain it but he was almost certain she was doing it on purpose.

- Nothing in particular, she simply replied.

- Nothing in particular, repeated Onii-san, his eyes staring at the void.

A cute announcement jingle rang in the hall as an automatic voice stated : "Due to heavy snow, we are reducing the number of trains. Thank you for your understanding."

- Do you think the trains will start running again ? she asked.

- Good question.

- If they don't... Can I come visit your place, Onii-san ?

The young salary-man could not stop himself from letting a loud gasp break through his lips, startled by her unexpected statement. Amused, Ai-chan slightly turned towards him, offering him a better view on her outrageously huge assets that she was keeping squeezed against each other. She perfectly knew that their tremendous size couldn't possibly be hidden by her pea coat, especially at this distance. She slightly tilted her head on the left and displayed a wide amused grin.

- What ? You do live nearby, right ? she asked with an innocent tone.

Onii-san could feel his cheeks turning to a bright red color, betraying how flustered he was. Ai-chan... at his place ? Immediately, a ton of images and dreams swirled in his mind. He pictured himself on the phone at home, explaining to his boss that the trains were not running and how unfortunate it was. After having cleared his throat, he would have asked his boss :

- Yes, I think I have no other choice but to take half the day off and I mu-...

He would have turned in the direction of his bed and stopped mid-sentence. There, he would have seen Ai-chan, sitting on the edge of her bed, vaguely watching the television. He would see her taking off her pea coat, widely opening her arms in the process. There, she would greatly arch her back, making her enormous breasts even more incomprehensibly huge. With each one about the size of a nicely ripped watermelon, she'll know that her eyes will follow their great curves, showing to him her profile silhouette. The snow that had fallen on her hair and skin would have already melted by her warmth, adding glitter to her magnificently shaped body. Hearing him stop mid-sentence, the busty girl would have looked at him with a smile and her big green eyes. There, deep in her beautiful pupils, he would have seen her immense power of self-confidence, teasing and arousement. Ai-chan would let her back arched just a few seconds too much for him to appreciate how divinely massive her bosom was and to properly show how intentional it was. Her coat finally removed, she would keep a straight position, sticking out her huge chest. She would keep looking at him with the same burning eyes while he couldn't look away from her body.

- Actually, please allow me to take the whole day off... he said as his voice lowered more and more as he kept appreciating his lover's body.

Ai-chan's grin would grow wider, visibly satisfied by his arousal and that he would take care of her for the whole day. She would lay down on its bed, making sure to make no efforts in controlling the jiggle of her enormous breasts in the process. From there, she showed Onii-san her thin legs, visibly inviting him to come with him. Her hair, slightly undone by her laying, would not prevent her piercing eyes to analyze every reaction he was displaying. Onii-san couldn't even hear his boss' angry reaction, mesmerized by this sight. He could only mutter absent-mindedly :

- I'm sorry, I don't think I can come to work today...

He would faintly hear his boss scream on the phone but he could only watch at her two inviting mountains heaving up and down with each one of her aroused breaths. He would hang up the phone as Ai-chan's smile would grow wider, filled with her pride that she would be so hot that he would rather sacrifice his job than to let her go. As he would be approaching the bed, she would keep her green kinky eyes still locked on his, even though his eyes were running everywhere on her divine body. Very slowly, she would invitingly spread her thin legs open, revealing to him her white pant-...

- Are you thinking about something lewd ? Again ? said Ai-chan from the present.

Onii-san gasped, violently brought back to reality, on the train platform with his embodiment of perfection and feminine sensuality. The person in question gave him a mocking look, visibly amused to have played him once more. As always, she was once step ahead, perfectly knowing what he had imagined in his mind as soon as she said she could come to his place.

- Ah ! Unfortunately for you, the train has arrived.

- Unfortunate... what ?

Ai-chan started walking towards the train and gave him a playful wink while she went in front of him. "My god" thought Onii-san, "how can she be so seductive !?". Did she just hint that his whole dream could have come true ? That if the train didn't come, she and him would have…They weren't even in the train and he could feel he was already hard.

As they both entered the train, Onii-san followed her teasing angel to their usual spot. Thanks to the train being late, the space became more and more crowded. It was not long before Onii-san's body was forced to be put in contact with Ai-chan's massive assets, something they were quite accustomed to. As he felt them against him, he couldn't stop himself from closing his eyes a few moments to savor the feeling of her incredible bosom. But the late passengers kept coming in more and more, squishing themselves trying to fit in. Onii-san's belly kept being pushed more and more onwards towards Ai-chan's soft pillows.

But the busty teenager soon sighed in slight discomfort as her massive bosom was hardly crushing the large wooden buttons of her peacoat against her protector's body. Onii-san could also feel them on his belly, greatly contrasting with the pure softness of her flesh. It was already painful to him so he couldn't imagine how she would feel. She softly tapped him on his arm, signaling him to move backwards. It was not difficult for her to make him understand what she wanted to do and he did it with great pleasure. He moved backwards, pushing the other passengers still grumbling at the train as much as he could. The pressure between them decreased and her imposing chest greatly seized the opportunity to fully expand back. But her chest was so imposing that Onii-san could not even leave a slight space between them despite his efforts. Yet, the pressure was reduced enough for her to slip her hands towards her front to remove these annoying buttons. As she was unbuttoning her pea coat, Onii-san was doing his best to hold the large flow of passengers unhappy to be squeezed as more people came inside. His arms were literally shaking to hold these few centimeters of relief. But his fight was greatly rewarded. Each time Ai-chan would unbutton one, he appreciated the jiggle of her friend's giant mountains. Little by little, with each bottom her massive chest was revealing itself more and more. But as she was doing so, Onii-san's jaw dropped more and more in disbelief. Somehow, she looked... larger. He couldn't see her face but he could guess she had a very large smile on it for some reason.

Finally getting rid of these large wooden buttons, she showed a cute beige sweatshirt that looked very warm with her usual shirt and tie beneath it. It was as pretty as the sweatshirt Onii-san imagined. Ai-chan looked away while making an innocent and cute face, she opened her peacoat wide to reveal how stretched her sweatshirt was by the sheer size of her two massive assets. But to Onii-san's now experienced eyes, something was different from his dream and he immediately knew what it was. Her chest was larger. Her two enormous mountains looked perfectly round and beautifully shaped by her outfit. Just like her part-time job uniform, it was clear that it was never designed to contain such tremendous masses which made them look even more impossibly huge. Looking away innocently, she was allowing him to take a nice look at the volume she was offering. But Onii-san knew her too well now, playing the innocent card was always one of her best tricks. She wanted him to look at her. There was no doubt now : she had grown.

Taking advantage of his trouble, the incoming passengers started to push back Onii-san towards her. Her deed done, Ai-chan just stood there innocently looking here and there with her big green eyes. Slowly, her mountains, being more and more squished by Onii-san's incoming body, started to overflow in every direction, spreading all across Onii-san's body. While the pressure increased more and more, Ai-chan let out a soft moan only he could hear. When they got back to their position, the pressure was beyond impossible. Finally rid of her pea coat and its wooden buttons acting as proxy, the lucky salary-man could feel just how incredibly soft the flesh of Ai-chan seemed against him. The feeling of her breasts' massive volume and softness was beyond anything he had yet experienced as the sweatshirt greatly emphasized these aspects. He never was squished this hard against her breasts, not even during their first time. They really felt enormous and gigantic at the moment. He felt like he could never understand just how tremendously big this teenager was. Each Monday served as a reminder to how colossal her breasts were. They were indeed so massive that even this close, they were preventing their lower body to touch, hiding his erection to her (although he was sure she probably knew by now). And this softness... My god, how was it even possible for them to be so soft ? Again, he did not have to see her face to picture the prideful smile she was always showing to him when her oversized chest became the main topic.

-Much better, isn't it? she said with a large knowing smile.

He nodded, making a face showing the outpouring of his emotions. She smiled while looking away, letting him enjoy the wonders of her body for a few moments. It was like she knew already that she had to let him slowly process how incredible she was. Even now, she still amazed him by how incredibly divine her chest was, whether it was with its sheer size, its softness and firmness, its smell or its perfect shape. To top it all and how heavenly it was, her breathing added movement as well as the feeling of weight.

Ai-chan looked at him and finally their eyes met. Seeing his trouble in his eyes, she asked softly with a faint smile :

- What's wrong?

Onii-san opened his mouth but no words left his mouth as Ai-chan breathed in at this very moment, crushing her divine assets on him.

- Is there something on my face?

- Ah... no... it's just... I...

He looked at her. She was beautiful. Outrageously beautiful. Just like in his dream, snow had melted on her perfect skin and hair, making her glitter. Her eyes and lips, more than anything else, seemed to sparkle. If only the trains were canceled, he could have maybe...invited her to his place. Should he have invited her for Christmas ? Maybe to a... love hotel ? He felt his cheeks turn red at the thought of it. Just thinking about her in a hotel room, seeing her being amazed by the decoration, eating the hotel's diner, seeing her leaving the shower with just a towel wrapped around her huge chest, imagining her lowering it to show her cleavage and asking him to make her a true woman...

- I was working... said Ai-chan's voice.

Onii-san gasped again, brought down to Earth for a second time.

- for Christmas..., she added with a knowing smile.

For sure, she knew that he would picture her in her waitress uniform. "Her tight waitress uniform", self-corrected Onii-san in his thoughts. He wondered if her shirt was able to hold her oversized breasts, considering she had popped a button when he was there last time.

- No one wants to work that shift so there's a bonus, she said.

The train finally went on strongly jolting, making Ai-chan's massive bosom jiggle heavily against him. Onii-san tried to follow the conversation but he immediately lost his focus as her two mountains crushed against him. He would have loved to see her in a waitress uniform during Christmas. Picturing her with her buttons struggling even more and a cute Santa Claus hat did not really appease his erection.

However, it was quite easy to read on his face. Ai-chan could perfectly see that he was enjoying himself quite a lot and that made her small smile even more seductive. She knew. She was perfectly reading his thoughts. While Onii-san was still daydreaming, she softly said :

- Are you relieved?

- Yes, he answered automatically.

Being brought back on Earth, he quickly corrected himself :

- Wait, no. Wh-w...Yes?.. N.. Wh-why w-w-would I be?

Ai-chan's look was even more teasing than usual. She was loving these little moments where Onii-san was panicking. She sighed, pushing an even greater force against his protector body, making him sweat even more.

- Personally... I don't want to grow up. Not yet.

Onii-san remained silent, waiting for more information. Was she referring at her age or... to her outsizing area? After all, she already went up one cup size since they first met, growing from an I cup to a J one. And from what he felt, not a small one at all. Could she be referring to that?

Ai-chan giggled happily, making her breasts jiggle against Onii-san's body. The sensation was impossible to describe with words.

- All my friends tell me they want to grow up, she continued giggling. But in my case...

Her giggling stopped and her voice took a deeper, more seducing tone. The kind of feat only Ai-chan was capable of.

-... Everyone is treating me as an adult.

She emphasized her statement by a deep sigh, crushing her titanic breasts against him. They were so impossibly huge that their sheer size stopped Onii-san's breath for an instant. He felt like her two gigantic mountains were pushing as hard as they could against him. It was so good... Ai-chan smiled again with her proud expression.

- So that's probably why I don't want to be treated that way, she said with a melancholic tone, lowering her head.

Onii-san looked down but could not see her eyes. After all, it was probably a difficult situation for her. Being a teenager with such tremendously huge breasts should be pretty hard sometimes. But as he was about to say something to recomfort her, the train shook hard while breaking, jostling everyone inside. The violence of the shake made Ai-chan fall and slipped with a scream 20 centimeters downwards. Her enormous chest stopped right in his hard crotch. Onii-san felt her flesh effortlessly gobble his private part in the giant softness just like their first time. But this time, he really felt that she was indeed larger than before. His cheeks turned vividly red of embarrassment. There was no way she couldn't have felt it. In her fall, he managed to catch her from slipping further but he was actually certain that it was more thanks to the friction force of her enormous breasts on him.

- Are you okay?

- Y-yes

With his help, Ai-chan managed to squeeze herself back up again, a task made difficult by the size of her chest. Soon, her two mountains left his crotch as she wriggled back up. With each one of her breasts bigger than her head with around 20 centimeters in diameter, there was not a single part of Onii-chan's lower belly that did not get squeezed by her gigantic assets. Finally on her feet, she emptied her lungs and arched her back, pulling as much mass as she could from the depth of their enclosed space and crushed with all its weight on Onii-san's belly, cutting his breath once again for an instant. They were so... heavy. So hefty. Doing so, the young busty teenager was easing the pain of her shoulders while innocently showing how heavy her bosom was. Onii-san gulped down. Just how massive were they ? Onii-san didn't dare to look at her. Surely, she must have felt how hard he was. Ai-chan sighed with a serious tone :

- Actually I lied to you.

His breath cut short, Onii-san looked at his busty angel. She was not looking at him but rather kept her head slightly down, although he definitely noticed a faint smile.

- The other day... I took another step towards becoming an adult

- Eh?

She did not reply immediately, letting him search while he could definitely see her big mysterious smile. The one smile she was always showing when talking about her breasts. A teasing, proud and boastful one. Onii-san could definitely see that it was related to that in some way and he had clues. Her breasts felt bigger, softer and heavier than when they first met. After all, even now and after all these meetings, he was still shocked by the sheer size of them. Each Monday, she somehow managed to amaze him even more by how massively huge her breasts were. And there she was with her straight back and shoulders opened wide to show as much volume as she could, still with her proud smile. This same goddamn smile. He had to ask her. He knew that she knew that his lips were burning with this question. Did she...

- Ai-chan ?

- Hmm?

He swallowed hard and whispered :

- Di-did you become K-chan?

Onii-san could not believe himself to have asked such a question. For the first time, he had asked a question about her breasts. They were no more innuendos anymore. He was craving to know now. For the sole answer, Ai-chan chuckled a bit and even though he couldn't see her eyes, he saw her smile grow even wider.

She replied softly in a whisper :

- No.

The train strongly jolted again, making Ai-chan's breasts jiggle heavily. Both he and her looked down at her bosom and appreciated her flesh jiggling almost in slow-motion. Onii-san kept himself from sighing to not trouble this amazing experience. It must have been a divine intervention to expose her lying. Onii-san was sure of it. She was larger than before. Without any more words, Ai-chan raised her arms to her sides and gently squeezed her forearms against her massive bosom, redirecting the tremendous flow of her soft flesh against him. Onii-san widely opened his eyes and his jaw dropped, shocked at what Ai-chan was doing. He would never have thought her to tease her this hard. By squeezing her flesh on the sides, she perfectly knew that her J-cup breasts could no longer spread on her sides. Doing so, she was purposely redirecting most of her gigantic volume on her protector's belly. Her smile was now as wide as it could get. She gently squeezed her breasts together three times, showing how enormous they were. During the whole process, the pressure was so intense that Onii-san could not even breathe and stayed there with his mouth open. She added in a faint teasing whisper:

- Not quite yet...

With a chuckle, she stopped playing with her gigantic assets and let go of her forearms. This let a bit of the pressure out by letting her breasts spread on her sides but it remained enormous nonetheless. Onii-san could eventually go back to his breathing but he remained with his mouth opened, shocked. Just how huge were her breasts? Just now, she admitted that she had indeed grown. Even though she denied having reached a K-cup, she was not very far from it. The young salary-man could only imagine just how full her bra was. She was not just any J-cup now, she was one who could fill it entirely. Melting and sweating profusely at the consideration of the sheer size of her beloved companion's bosom, he almost did not hear the message of the train restarting. It was the feeling of the tight jiggle of his friend's assets against him that informed him.

Ai-chan remained silent for these few seconds, again leaving him time to process what happened. She kept a faint but smug and proud smile on her face. After all these meetings, she knew that she sometimes needed to let her Onii-san understand how incredibly massive and divine her bosom was. Being this squeezed against him, saying that she was on her way to reach her K cup and pushing her breasts forward against him... That was a bit too much for him to handle. Seeing him all confused about her body made her giggle softly.

- No, that's something more definitive, she said, restarting the conversation.

She felt Onii-san gulping down and his trembling excited voice asking :

- S-so.. Wh-what happened?

Ai-chan looked up to the face of her Onii-san that lowered his to meet her big green lovely eyes. As usual, they were burning with tease and seduction. But they had something more to it. They sparkled just like they always do when she was about to give her an incredible information.

- It was my birthday! she said with a big large smile.

- Oh! Congratulations!

Onii-san smiled back at her. He sighed and Ai-chan could definitely see that he was relieved that it was not another tease. Her large smile turned into a grin and her eyes sparkled before she continued :

- I turned 16.

Her piercing eyes stared right at him as she lowered her eyelids. Again, her large smirk indicated she enjoyed the situation a lot. Onii-san thought he was going through an X-ray vision, analyzing every expression his face would make. But it was too much for him. 16. 16 years old. Ai-chan was 16 years old. She was so young. How could she have such a body forged and perfected by the gods. Immediately, this number rang like a bell in his head. In Japan, she was now legal to have... well, to get intimate with her. He knew his face melted with this new information and that she had a great pleasure seeing that.

- Wh-wh.. Wha..

But he could not even find the words. The train rattled again and he felt her enormous mountains' masses moving against him. Trying to maintain composure, he gulped down as sweat drops were running down his forehead and spine. Too many things were happening at the same time for him to process.

- S-so... Th-that means y-you're... You're a first-year!?

Ai-chan tilted her head on her side with amusement :

- Eh ? You did not know about that?

Everything in her tone sounded as she perfectly knew he had no idea about it.

- W-well, I thought you-you were at the very least a second-year and...

Onii-san stopped, his mouth opened. A terrible yet beyond incredible thought came to his mind. Articulating every word, he stuttered softly :

- D-does that mean...

Onii-san gulped down.

- Y-you w-were o-only... 15 ?

Ai-chan giggled with the same mocking laugh when her teasing worked. Onii-san was visibly dumbfounded.

- Huh? What are you trying to say?

Onii-san remained there silent, his mouth opened in disbelief and amazement. As the train was slowing down, she leaned forward a bit, letting her breasts crush against him even more but this time purposefully.

- Don't hold back, she giggled with a big smile.

But it was too much to handle. For months, every Monday, he was teased by a 15 year old girl. And this girl, at such a young age, not only managed to fully fill an I-cup bra to the point that she had to step up to a J-sized one but she was growing even more ! For months, he felt the delicate and beyond-this-world flesh pressed against him, with all its softness and firmness of youth. And by the time, this young girl reached her 16 birthday, she filled more and more of her J-cup to the point that the K-sized one was not that far away. And all of that was maintained in the high-school uniform of a first year. Onii-san could not even answer that. Actually, how could he answer her? He couldn't tell her how amazed he was. But it did not matter because he saw in her eyes the soft fire of pride and confidence burning. She was not expecting any answer because she already knew the effect she was having on him. As the train stopped and the crowd was leaving the train on the platform, she carefully pushed her massive assets against him, artificially maintaining the pressure as long as she could on him. Understanding it, Onii-san's dumbfounded small brain barely managed to keep playing her game and he stood his ground to allow her to crush her heavenly body on him. Almost from nowhere, she raised her right arm in between their faces. In between her thin index and thumb she showed him a small button. Onii-san sighed : once again, her chest had popped a button from her school uniform earlier this week. With a chuckle, she slipped it in his breast pocket and gently tapped it, adding a playful wink. The busty girl then started to escape from their inclosed space. Her two colossal mountains rubbed against all his belly and right arm as she slipped on his left. When she slipped past him, Onii-san felt her left breast bouncing back heavily in its tight bra cup, quickly followed by the right one that bounced with the same heaviness. He turned around, following her with his mouth still opened. Ai-chan gave him a look above her shoulder, showing the profile of her bigger-than-her-head breasts tightly maintained in her sweatshirt. Her ginormous mountains bounced heavily with her walk, proud to show their recent growth. Her beautiful eyes lowered to his crotch area before coming back at his eyes again. With a big large knowing smile, she sensually winked at him :

- Have a nice holiday ! she giggled.