Sofia was lying on the couch, lazily watching television without paying much attention to it. She had nothing planned for the day, no training or photoshoots for her modeling job, and as often happened when she wasn't busy being flattened somewhere, she was bored to death.
While Sofia was wondering what she could do today, Carla came down the stairs and walked through the living room toward the kitchen, yawning loudly, still in her pajamas and barefoot: "Yaaaaaawn... Good morning, Sofia" Carla said as she entered the kitchen. Like most days when she didn't have classes at university, the older sister spent most of the morning sleeping, waking up at embarrassingly late hours.

Sofia got up from the couch and followed her sister into the kitchen without saying a word. After a long sequence of SQUISH!, Sofia went back to lying on the couch, but this time she began bouncing and catching a rubber ball the size of a baseball against the wall.
This ball was made from Carla's crumpled body, squished and compacted into that small spherical shape: her squished face occupied much of one side of the sphere but was almost entirely covered by the soles of her flat bare feet pressed against the surface, leaving only her eyes visible, with a confused expression due to the continuous bouncing she was forced to endure. The rest of Carla's body was disorderly compacted on the remaining surface of the ball.

Sofia continued to bounce her sister against the wall and the floor, but even this didn't remove the bored expression from her face. "Ugh, not even my favorite squishy toy can entertain me today... What could I do?" she thought, catching Carla and beginning to squeeze her in her hand like a stress ball.
Suddenly, Sofia had an idea, and she pulled out her smartphone. "Let's see if Mia is free today" she wondered, starting to text her friend while continuing to torment her sister with her other hand.

<Heyyy, how's my favorite ball doing?> Sofia wrote. The message was immediately seen, and Mia began typing a reply.
<Next time, you won't be so lucky, trampoline girl>
<We'll see... Hey, are you busy today? Want to do something?>
<I was planning to hit the gym later, but I'm free now. Want to hang out in the city first? Then we could go to the gym together>
<Sounds good. I'll come by soon>

Sofia jumped up from the couch but stopped in the middle of the room, looking at Carla's spherical and squished body in her hand, unsure of what to do with her. She finally made a decision and nonchalantly stuffed her sister between her ample boobs. "She probably has nothing to do anyway, might as well take her with me... It's always handy to have an all-purpose squishy toy for any situation."
After freshening up and changing into comfortable clothes, Sofia grabbed her gym bag and was about to leave the house when she found a piece of paper hanging on the door, with Carla's bag attached to the handle.

The note read: "I have to meet some friends downtown. If you're going too, could you give me a ride and bring my bag? Thanks, Carla" Sofia opened the bag and saw Carla's belongings, a change of clothes, and a pair of sandals inside.
Sofia was speechless. "How the hell did you know..." she said in astonishment, referring to her cleavage where her sister was still squished inside. She thought she heard a faint amused murmur from between her boobs.

"Cut it out with the superior attitude!" Sofia said irritably, pressing her boobs together under her shirt and squishing Carla even more between them "I'll do you a favour this time, but don't make it a habit!" Sofia concluded, grabbing her sister's bag and leaving the house.

*****************************************

It was a beautiful spring day outside, and Sofia and Mia were heading towards the city center, each carrying their gym bag. As they walked, they were passing a strange soccer ball back and forth, sometimes kicking it on the ground, sometimes juggling it in the air.
This ball was none other than Carla, who had retained her previous spherical shape but had grown to her current size of a soccer ball, still with her bare feet covering much of her face and always with a disoriented expression, due to her current job as a ball.

"...and so, before coming to you, I went to the garage and inflated her with the pump until she was a perfect soccer ball!" Sofia concluded her story, juggling her sister on her thigh. "Pretty much the same thing I did to you the other day for training" she added, looking at her friend with a mocking air.
"No need to remind me," Mia responded with a fiery expression "By the way, keeping me in that state after training and using me as a pillow all night was a low blow. I'll return the favor one of these days... I'm sure you'd make a perfect blanket!"
"Bring it on whenever you want!" Sofia replied, juggling the ball one last time and passing it to her friend.

"Anyway, you two sisters have quite a nice relationship, I would say" Mia continued, catching Carla with her hands and bouncing her on the ground like a basketball, her body briefly squishing against the ground with each bounce before returning to Mia's hands "Lately, I always see you together, though I have to say at least one of you is always squished into some strange form."
"What are you talking about?.." Sofia began, surprised by her friend's sudden change of topic. But as she was about to instinctively retort, she realized that she had indeed spent a lot of time with her sister lately, even if mostly due to their squishy shenanigans.
"...It's just that I can't stand her superior attitude, like she's better than me. And she's a total slacker, but excels at everything she does effortlessly. It's not fair..." Sofia said, her voice low and her demeanor very different from her usual arrogant self. "It really pisses me off, and that's why I feel like squashing her" she concluded, looking down at the ground.

"Well, at least now your relationship, as strange as it is, seems better than it was some time ago, right? Until last year, you two weren't even talking, if I remember correctly" Mia responded with a serious expression.
Sofia nodded without saying anything. During that period, she and Carla barely even looked at each other, and only recently had they started interacting again, thanks to their squishy shenanigans. She had finally found something in which she could relate to her older sister as an equal... even if Carla was, of course, much better at turning herself back to normal, as expected.
"You know, I kind of envy you two sisters. Since my older brother moved to another city, we rarely see each other... I miss the daily relationship we had" Mia continued, holding Carla's spherical body and tossing it to her friend, who caught it effortlessly "It's clear as day that Carla really cares about you. You should be grateful to have an older sister like her to share good times with".

Sofia looked at her sister's spherical body, which still showed a dazed expression; likely, Carla hadn't heard any of that embarrassing conversation. "Yes, I'm lucky to have Carla as a sister" she said quietly, a smile on her face, just before squeezing the ball between her hands, letting the air inside of her out.
"But that doesn't stop her from also being my favorite squishy toy!" Sofia said in her usual arrogant tone, beginning to deform her sister as she pleased "Haha, that's the Sofia I know!" Mia laughed, watching the scene. Those two sisters were a lot of fun!

As they continued walking, the previously deserted street became increasingly crowded as they approached the city center. After a few minutes, the two girls and the squishy toy arrived at the bustling central square, alive with activity thanks to the beautiful day; the many shops and cafes in the center had become the chosen destination for many people that afternoon.
Among the crowd, Mia spotted Jane sitting on a bench with another unfamiliar girl, dressed inconspicuously, with a long fringe covering her forehead and part of her face. "Hey, Jane" Mia greeted, approaching the two girls along with Sofia "And I don't think we've met... I'm Mia, and this is Sofia, Carla's younger sister" she said to the unknown girl.
Jane stood up and smiled at Mia, while the girl, startled by the unexpected and direct approach, instinctively stepped back behind Jane, muttering incoherently with her head down "Good afternoon, Mia. This is Emily, a classmate of Carla's. She's not very comfortable around people she hasn't met before, but she's also happy to meet you" Jane said, giving Emily a gentle nudge on the back. Emily managed a smile in Mia's direction, lowering her head in greeting.

Sofia abruptly interjected, addressing Jane: "You're waiting for my big sister, right? These are for you" she said, tossing Carla's bag carelessly to Jane, who caught it in her hands. Then she removed the bracelet from her wrist to offer it to the two girls, eliciting a sigh from Mia.
Jane and Emily approached to take a closer look, realizing that what they initially thought was a bracelet was actually Carla's squished body, twisted into itself. Her arms were raised above her head and joined to her bare feet, forming a donut-like shape. Carla's expression was ridiculous, reminiscent of a cartoon character knocked out, with wide eyes and an open mouth sticking out her tongue, caused by the amount of punishment she had endured during the journey.

Jane looked at Sofia with a resigned expression, while Emily quickly took the bracelet that Carla had become, admiring it like a treasure: "Did you do this to her?" she asked Sofia in a deadly serious tone, approaching her and looking her in the eye.
"Y-yeah, why? Got a problem with that? She's my sister and I'll squash her as much as I want" Sofia replied defensively, instinctively stepping back, taken aback by the sudden change in the small girl's demeanor.

"Could you do the same to me?!" Emily asked enthusiastically.
"Huh?" Sofia, Jane, and Mia said in unison. "Carla and I could be matching bracelets, that would be fantastic!" Emily continued, looking at Carla's squished body in her hands with a dreamy expression "So, can you do it?" she asked Sofia again, full of expectation, her previous shyness a distant memory.
Jane and Sofia were speechless, and it was Mia who suddenly broke the silence with a loud laugh. "You’re such an interesting girl, Emily!" she said, patting the small girl on the head, who barely reached Mia's shoulders.
"Don't worry, I'll handle your request" Mia lifted Emily effortlessly and began to forcefully squish her body, attracting curious glances from passersby, which Jane quickly responded to with reassuring gestures.

When Mia finished her work, she held Emily's body, squished in the same donut-like shape and size as Carla, with her arms above her head joined to her feet, an enthusiastic expression on her face. Mia took Carla and Emily and slipped them onto Jane's wrist, where they stayed like normal bracelets. "There you go, now you're two fantastic matching bracelets!" Mia said, satisfied.
Jane was stunned for a moment: "..Thank you Mia, and thank you Sofia for bringing Carla. We’ll be going now, have a good day" Jane said politely, hurrying away from the two girls, sighing as she looked for a secluded place to return her friends to normal.
Why did she always get involved in these shenanigans? Looking on the bright side, at least this time she hadn't been squished, she thought with relief. Emily, on the other hand, was over the moon about spending time so close to her idol, while Carla, still quite dazed from all she had been through, began to regret asking her sister for a ride.

Sofia remained speechless, watching Jane walk away. "My sister sure has some strange friends" she finally said.
"Says the girl who handed over her sister to her friends in bracelet form" Mia said with an amused expression.

*****************************************

After a pleasant walk through the city center, Sofia and Mia decided to head to the gym. "How about we warm up with a jog to the gym? It's definitely better than doing it indoors on the treadmills" suggested Mia.
Sofia was already planning to get back at Mia for the treadmill prank from last time, but she agreed readily: "Alright, but let's make it more interesting: whoever gets halfway first can squish the loser however they want until we reach the gym" Sofia replied with a challenging expression "I like the way you think" Mia retorted in kind.

After changing, Sofia wore her usual workout outfit: black shorts, a black sports bra to contain her ample chest, purple running shoes, and a matching purple headband to tie back her hair.
Mia, on the other hand, wore white leggings, a tight white and orange shirt that highlighted her amazing abs, orange running shoes, and a white headband holding back her moderately short hair. She was taller than Sofia, with more defined muscles while maintaining a slender physique.

The two friends started running, initially chatting amicably, but gradually picking up the pace as they approached the halfway point. In the final stretch, Sofia and Mia were sprinting shoulder to shoulder, putting in disproportionate effort for a warm-up.
In the end, Mia managed to pull ahead just enough to secure the victory. The two girls collapsed to the ground, panting from the exertion, until Mia got up and walked menacingly toward her friend "And now... my prize!.." she said, still out of breath.
Sofia, too exhausted to protest, was squished and balled up by the winner. "I just so happened to bring this for any eventuality" Mia continued, pulling a mini bicycle pump out of her bag and starting to use it to turn her friend into the desired shape.

At the end of the process, Sofia's body had taken on the shape and size of a soccer ball, similar to her sister a few hours earlier. Her enormous squished boobs were occupying most of the surface of the sphere, almost completely covering her face to prevent air from escaping. Her eyes, still visible, showed an irritated expression, her arms were aligned along her sides on the sphere, and the soles of her purple shoes were flattened on the lower side, leaving her legs compressed between them and the rest of her body.
"Don't look at me like that, the terms were clear" said Mia, addressing the ball before letting it drop to the ground and starting to run "Consider this a revenge for the other night!" she continued, heading briskly towards the gym while kicking her spherical friend and carrying both gym bags.

Upon arriving at the gym, Mia tucked Sofia under her arm, who displayed a dazed and disoriented expression. As they entered, the receptionist greeted them warmly: "Good morning Mia, and that’s Sofia, right?" she said, not at all surprised by a situation that had occurred many times before.
Mia responded to the greeting with a nod and headed to the locker room, where she put down the bags and began working on Sofia's spherical body. After a short while, POP! Sofia returned to her original form. "You got lucky, Mia, but you don’t stand a chance in the next challenge!" Sofia immediately said, challenging her friend.
"I wouldn't ask for anything else" Mia replied in kind, with a determined but clearly amused expression.

As per their usual routine, the loser got to choose the next competition, and after a few minutes, Sofia and Mia were both on the gym's wrestling ring, barefoot. Sofia had proposed a freestyle wrestling match, but with their personal rules, where the goal was to be the first to squish the opponent.
"Are you sure you want to choose our freestyle wrestling as the challenge? Remember, the last few matches always went my way" said Mia, bouncing on the spot to warm up, confident as ever. But Sofia responded with an arrogant smirk, "Who knows, this time it might turn out differently" she replied, determined to dethrone Mia from her primacy.

The fight began with an initial exchange of blows, where neither girl seemed to gain the upper hand: Mia's strikes were direct and fast, but Sofia's footwork allowed her to dodge and counterattack. However, Mia managed to land a hit by grabbing her friend's shorts: "Gotcha!" she said, smiling and lunging forward to grab her.
Sofia, however, was waiting for this: she freed herself from the grip with a spin and used Mia's forward imbalance to grab her and throw her to the ground, pinning her with a hold. "Nice move, but your ground holds suck" Mia taunted, moving to try and break free "I'll get out of this in no ti—UMPFF!" she tried to continue, but her face was inexorably flattened to the ground by Sofia's enormous boobs, which she had dropped onto her.
Sofia wasted no time and pressed Mia's helpless body into the ground until her entire body was flattened on the ring, a few centimeters thick, stuck in the position Sofia had thrown her into, her face showing an expression of extreme annoyance with one eye closed and her mouth distorted into a grimace.

"What were you saying about my holds, flattie?" Sofia said smugly, while the Mia-pancake on the ground hadn't yet recovered from the squishing and couldn't reply "I'd say I won this match!" Sofia announced, and she began to further squish her friend's body until it took the desired shape.
Mia's body had taken on a flat rectangular form, consisting from bottom to top of her bare feet, her long legs, her torso, and finally her head. Her chest was slightly expanded due to the squishing, and her face still bore the expression of annoyance, which had become almost comical due to the stretching it had undergone.

"Perfect, now you'll help me with some bodyweight exercises" Sofia said, rolling up her new yoga mat and heading to the part of the gym dedicated to such exercises, carrying Mia under her arm.
Once she arrived, Sofia placed the rolled-up Mia on the ground and gave her a tap to unroll her, laying her entire body flat and allowing Mia to speak: "Enjoy the victory, because next time I’ll—" SQUASH! she started, but was silenced by Sofia's butt sitting on her face "Shhhh, yoga mats don’t talk" teased the victorious Sofia, lying back along the rest of the mat and starting a series of sit-ups.

A few minutes later, the two girls were facing off in the next challenge chosen by Mia, which was barbell squats: in this case, there was no real competition, with Mia finishing the set while Sofia collapsed to the ground exhausted.
"Pant... Pant... cursed... gorilla woman... all-muscles..." Sofia gasped, but immediately regretted her words as she saw Mia's expression, which for once was not amused at all but deadly serious, a vein pulsating on her forehead "You know, I wanted to give you a light punishment this time, since I chose my specialty as the challenge, but suddenly I changed my mind.." she said, approaching Sofia and reaching out her hands.
Shortly after, Mia was punching a speed bag as part of her training, composed of Sofia's flattened and compressed body, with her two huge boobs forming much of the surface of the object, while the rest of the body was squished into the upper part of the speed bag connected to the support, the face not visible stuffed amidst all her other body parts.
"Finally those huge melons you have come in handy for something, all-boobs woman" teased Mia, still with a bitter edge from the previous comment, although she seemed very pleased with this particular training.

The next challenge was a jump rope contest, with the two girls striving to jump as fast as possible, the two ropes barely visible as they jumped.
Due to the jumps, Sofia's huge boobs swayed a lot despite the immense effort of the sports bra to keep them in place, causing the curious glances of some gym-goers who stopped to admire the spectacle: however, the stern looks of the two girls were enough to disperse the crowd that had gathered in front of them.

In the end, Sofia won the challenge, wasting no time in taking her friend's body to squish it as she pleased: after the squishing, Mia's body had taken the shape of a dumbbell, with one of the weights formed by the shoes and part of the compressed legs, the central handle composed of the rest of the legs and the compacted and elongated torso, while the remaining weight was made up of Mia's boobs and face, compressed in a disorderly manner.
Satisfied with the result, Sofia grabbed another dumbbell of similar weight and began training, lifting both the dumbbell and Mia in turn, a satisfied smirk on her face: "You're too light in this form to be a real workout, but I think I'll enjoy it anyway" Sofia gloated, squeezing and compressing Mia's elongated body even more.

Some time and several challenges later, Mia and Sofia were face to face in the weightlifting area, near the barbell benches; both were quite exhausted from the mixed training and various flattenings, but they were also extremely determined not to give in to their rival.
"We're tied, Sofia, as usual. The next challenge decides everything" announced Mia, slightly panting and looking Sofia in the eyes.
"The winner takes it all and gets to take the loser home for the evening" Sofia replied without hesitation, rivulets of sweat running down her forehead, reaching out her hand toward Mia
"Deal!" Mia decided, gripping her friend's hand tightly.

The final challenge the two girls had agreed upon was to lift the barbell with the heaviest weight possible, with the backrests of the two benches placed diagonally: both barbells had been loaded with an exaggerated amount of weights, but in the heat of the competition, the girls had thrown caution to the wind.
Sofia and Mia positioned themselves and began to lift the two barbells upward, but they were so heavy that it was difficult to even lift them off the support they were resting on.
The two girls looked at each other, and with all their remaining energy, they managed at the same moment to lift the two barbells, extending their arms upward. But almost instantly, their arms gave way, and SQUISH! the two barbells fell inexorably onto the bodies of the two girls and began to roll along the bench, flattening their bodies as if they were rolling pins.
When the two barbells fell to the ground with a thud, the two bodies of Sofia and Mia lay flattened on the benches, several centimeters thick and slightly elongated, their arms stretched upwards, the torso and upper legs flat on the bench, only the lower legs and feet still in three dimensions, both faces flattened and frozen in a strained expression; Sofia's boobs had expanded due to the flattening, spreading beyond the silhouette of her body.

Summoned by the commotion, the gym receptionist arrived and saw the state the two girls were in, with a resigned expression: "Again? It's the third time this year... Punishment is needed here" she decided, with a mischievous expression.
A few minutes later, a notice board had been hung on the wall in front of the weightlifting benches: on a large-lettered sheet, it read "DON'T END UP LIKE THESE TWO! ASK FOR HELP FROM A SPOTTER WHEN USING BARBELLS!", and below it, the flattened bodies of Sofia and Mia had been hung, still stuck in the futile gesture of lifting, their bodies completely two-dimensional, swaying like paper sheets as people passed by.

Results of today's challenge: a very flat tie.