Girl's Inflated Belly Challange by 40P (2024)

Girl’s Inflated Belly Challange by 40P

Air enema with a speed of 3000cc/h.
From going to school to leaving school (approximately 10 hours), I made full use of events to survive.

I added the illustrations using NovelAI.
(The text is handwritten by me, not by AI.)
I came up with it later, so the text and the picture are slightly different, but…well, I’ll see about it next time.

[Anna]

8:00, in front of the main gate of a certain school.
Click! Vvvvv…
When she passed through the gate, the anal plug inserted into her butt was activated.
“Ugh!?”
A young girl shook her long black hair with her thin eyebrows furrowed and her hand on her belly.

The plug sucked in the surrounding air and pumped it into Anna’s belly.
The speed was about 3000cc per hour.
This wouldn’t stop until she had passed through the main gate again after school again (18:00).
10 hours left.
The girl’s challenge had begun.

Anna took out her smartphone and opened her messaging app.
Her younger sister Yuuna’s talk history states this:

“Yuna is in my custody.”
(Picture of Yuna naked and bound to a chair)
“Follow the instructions and no further harm will come to you.”
“First, receive a small box at the locker in front of the station. The number of the locker is…”

…

“It looks like you received the small box.”
“Put that thing inside your ass and go to school at 8 o’clock tomorrow.”

Anna followed the instructions and inserted the anal plug that was in the small box into her butt.
And exactly at 8 o’clock, she arrived at the main gate of the school.
Suddenly, Anna’s smartphone vibrated.
It seemed like a new notification had arrived from her messaging app.

(Photo of Yuna naked and tied to a chair)
“Don’t tell anyone.”

Grrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr!
A loud sound echoed from Anna’s stomach.
“It hurts, it hurts!! Oh, my stomach… what’s this…?”
The air pumped in from her buttocks was wriggling in her belly.
Due to her body size, the amount that could fit in her belly was about 5000cc at most.
In other words, Anna’s belly would be full of air in about two hours.
If she didn’t find a way to get some air out by then, her stomach would explode.
Anna put away her phone and headed to her classroom.

15 minutes had passed.
At 8:15, the bell chimed.
750cc of air had accumulated in Anna’s belly.
She seemed to be feeling uncomfortable and had been stroking her belly many times since earlier.
“Good morning.”
When Anna took her seat, a girl with a red ribbon on her head greeted her.
It was Anna’s best friend, Otono.
“Ah, that’s right. One of the rumours at this school was about a small accident 10 years ago…”
Otonon, who recently became the head of the occult club, talks to Anna with shining eyes.
“Hey Otonami! No scary stories allowed in the morning!!”
The girl, her cheeks bulging, came to Anna and Otona’s side.
It was Miyuu, another close friend of Anna’s.
“Now is the good part. Her internal organs are coming out of the girl’s stomach…”
“Noaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa!!”
Miyu covered her ears with both hands and screamed.
A usual morning scene.
Anna continued to stroke her belly with a sour expression on her face as she watched this.

30 minutes had passed.
At 8:30, the chime sounded to signal the start of home room.
1500cc of air had accumulated in Anna’s belly.

The home room teacher entered the classroom.
“Rise! Bow! Be seated!”
Anna quietly listened to her teacher’s story.
A few minutes passed…

“Ugh…”
Guguuuuuuuu~~~~!!!!
A small voice leaked out from Anna, and a sound echoed from her belly.
Clenching her teeth, arching her back, she placed her hands on her stomach.
Her belly became plump from the large amount of air pumped into her.
“Haa, haa, haa…”
Anna repeatedly raised and lowered her shoulders and took shallow breaths.
Her body was shaking and large beads of sweat were running down her forehead.
“Anna, are you okay?”
The person who was secretly talking to Anna was Otona who was sitting next to her.
In response to her question, Anna shook her head slightly.

45 minutes had passed.
At 8:45, home room ended and the chime for break sounded.
2250cc of air had accumulated in Anna’s belly.

Anna rushed to the bathroom the moment the chime ended.
She went into a private room and took off her uniform, she then quickly checked on her belly.
“W-what is this!?”

Anna’s belly curved and swelled further.
Her belly was filled with air and expanded into a balloon-like shape.
Stroking her belly felt moderately tight, but pressing into it, it would flex and dent a bit.
“It hurts… my stomach… hurts…”
Anna was sitting on the toilet, blushed and breathed, but nothing came out because the anal plug was in the way.
Then there was a knock on the toilet door.
“Are you okay? Can I go to the pool first?”
It looked like Otono came to check on Anna.
“Yeah, it’s okay, just go first.”
“Got it.”
After saying that, Otane quickly left.
Today’s 1st and 2nd periods were pool.
Anna put on her uniform and came out of the bathroom, she then headed to the changing room.

60 minutes had passed.
At 9:00, the break ended and the first period chime sounded.
3000cc of air had accumulated in Anna’s belly.

Otono came out of the changing room after changing her clothes.
“You’re running late, so you better hurry.”
“Yeah, I’ll go right away.”
When Anna entered the changing room, the other students seemed to have finished changing and no one was there any more.
She took out her swimsuit from her bag and quickly started changing.
Her breasts were still in the process of growing, but her waist was widened and she had a solid female body.
When she removed her skirt, her belly popped out.
The pressure of her belt left a clear red mark on her belly.
“Hush, no, no, no… my stomach is like this…”
Her body was so thin that she looked like she was severely constipated.
In fact, there was so much air trapped in her belly, so she was still kind of constipated.
“Uuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuuu it hurts…”

Anna put on her swimsuit and stroked her belly.
Her swimsuit was a one-piece type, so it was easy to put on and take off, even if her belly was exposed and inflated.
Thanks to the frills, her belly was not very noticeable either.
Anna’s smartphone vibrated again.
It seems like a new notification had arrived from her messaging app.
“You can’t be serious!”
Anna looked at her smartphone and raised her voice.

“If you follow the instructions I’m about to write, I will allow you to excrete.”“Instruction: Swim 1500m in the pool.”

Anna was not a good swimmer.
She had never swum 1,500 meters in her life.

70 minutes had passed.
9:10, 40 minutes left until the end of first period.
3500cc of air had accumulated in Anna’s belly.

Anna sneaked in among the students who had already finished gymnastics.
Although her belly was hidden by the frills, her belly was still somewhat noticeable, but she subtly hid it with her hands.

According to the teacher, it looked like both 1st and 2nd period were going to be free swimming today.
Anna joined the other students in the pool.
“Jujujuju!!!”
“It’s cold! It’s cold!”
The pool has human-warm water.
The students around her looked at Anna with strange expressions.
It looked like the anal plug was sucking in water from the pool and pumping it into Anna’s belly.
Although the water was as warm as human skin, it had a lower temperature than her stomach.
“Ugh!!”

It appeared that the cold water containing chlorine entered her intestines, causing her to immediately develop abdominal pain.
Anna gritted her teeth as she felt the pain tightening.
Luckily, she didn’t defecate thanks to the anal plug.
“Yo, alright, let’s go!!”
Anna kicked the wall and slowly moved through the water, raising her head and breathing heavily.
“Puhaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaah…”
She reached the 100m turnaround point with a slightly clumsy breaststroke.
Anna put her legs on the bottom of the pool, flipped her body over and went back in the breaststroke.
“Puhaha, haa, haa, haa…”
Anna had returned to where she started.
It took her about 5 minutes to swim 200 meters.

At this pace, She thought she could barely swim 1500m in the first period.
“Aaah, sooo!!”
Anna took a deep breath and began breaststroke again.
This time, she swam 600 meters in one go, taking about 15 minutes.
“Haa, haa, haa, haa…”
Anna seemed to be getting tired and took a short break.
Although she was not a good swimmer, her pace was fast.
Her belly, which was full of air, might have been acting as a float.
“Burp!”
Anna let out a loud burp as she stroked her belly with her hand.
Her belly loomed larger than before she entered the pool, becoming more rounded under the pressure of her swimsuit.
20 minutes had already passed and nearly 1000cc of water had accumulated in my stomach.
But water, unlike air, was not compressible.
Her belly was full of air, so even a small amount of water caused her belly to swell considerably.
“Suu!!”

She took a deep breath and started swimming again.
This time, the swimming pace was slower.
Even though it was still 100m before the turnaround point, it took more than 5 minutes.
Anna swam with her feet touching the bottom of the pool many times.
It seems that as her belly protruded, her lower back arched and her body sank, making it impossible for her to move forward.
Her belly swelled even more, making it difficult for her to even breaststroke.
“Haa, haa, ugh, uh… it hurts…”
Anna finally stopped her movements while holding her stomach in the middle of the pool.
She had over 600m left to reach the designated 1500m.

110 minutes had passed.
At 9:50, the first period ended and the chime for break sounded.
3500cc of air and 2000cc of water had accumulated in Anna’s belly.

Sirhhhh…
Suddenly, it began to rain heavily.
Other students got out of the pool and went back to the locker room.
“Oh, my stomach… is…!?”

Anna was still in the pool holding her stomach.
Due to her body size, the amount that could fit in her belly was about 5000cc at most.
More than that amount had been pumped into Anna and her belly looked like that of a pregnant woman about to give birth.
“I-I… I… I need help…”
Combined with the cold from the rain, Anna was shivering and couldn’t make a sound.
The sound of even heavier rain drowned out Anna’s weak voice.
She could hear the sound of a swimmer coming from the side of the pool.
“It’s cold, I’m going first!!”
After saying that, Otono ran to the changing room.

120 minutes had passed.
At 10:00, the break ended and the chime for the second period rang.
3500cc of air and 2500cc of water had accumulated in Anna’s belly.

Only the sound of rain echoed in the deserted pool.
Anna slowly crawled out of the pool.
She could hear bubbling sounds coming from her belly.
The anal plug seemed to be sucking in air and pumping it into Anna’s belly again.
“Ugh, ugh, gebuu!!”
When she went up to the poolside and held her belly with both hands, she drooled profusely.
However, as if it had been rigged somehow, none of the air or water that was stuck in her belly would come out.
“Oh, my stomach… my stomach…”
Anna quietly stood up and headed to the changing room.
She quickly took out her smartphone from her uniform and opened the messaging app.
In her talk history, there was a photo of her younger sister Yuna, naked and tied up in her chair.

“I cannot take it any more”

Anna typed a message on Yuna’s chat with trembling hands.
She waited for a reply.
“Haa, haa, haa… ugh, ugh, uh!?”
Anna looked down, holding her stomach with the hand that wasn’t holding her smartphone.
The sweat dripping down her cheeks didn’t fall on the ground, but on her protruding belly.
Then, Anna loosened her shoulder straps and began to take off her swimsuit.
Her small breasts were still swollen and her white, delicate body was barely tanned by the sun.
Her belly bulged as it was released from the pressure of her swimsuit.
Its belly was full, like that of a well-fed cow or donkey.
“Ah, Anna!?”

When she looked in the direction of the voice, she saw Miyu standing there.