[ABDL, Diaper Use, Soiling, Mental Regression]

Incontinence. The act of being unable to hold in anything within one's bladder or bowels, making a complete mess of whatever you're wearing down below. A critical condition that was spreading across the seven seas, all thanks to the Infitting compound that was being distributed from Maidens' Dream and the agreements that they made with several bases dotting these seas.

Two of the ships that were currently suffering from a developing case of this infernal condition were the Sakura Empire crane sisters, Shoukaku and Zuikaku. As one of their rivals, Akagi, had been at the forefront of this deal between their base and the source of all these rapidly regressed babies... It meant that she specifically wanted to bully them into joining her in pants-filling bliss. Something that they were greatly opposed to, and it wasn't just because it was a suggestion that came from her.

Unfortunately for both of those adorable crane sisters, they had no say in the matter. Their Admiral, who was currently having a bit of fun with Akagi given the subtle cries that echoed out over the intercom, had forced them to just accept this new standard of living. Which meant that they, like many other boatgirls stationed at this base, were forced to consume tiny doses of this compound during their regular meals.

The results? They had developed an acute case of incontinence. And while Zuikaku, the younger of the two crane sisters, had started to accept part of this treatment by the way that she wore the Sakura Empire print diapers that were readily available throughout the base, Shoukaku remained steadfast in her attempt to resist. She wore her panties, no matter how humiliating it would be to mess them. She just had to intercept and deal with the messes as they came, that way she would keep some amount of dignity.

Even if they had started to grow used to their current condition, they would try to resist in their own way. Which was why they had taken their lunch with them to their shared dorm room, preferring to at least make a mess in privacy if they couldn't make it all the way to the toilet.

That, and the less they were seen like this, the better. Whether it was the brown-haired and otherwise determined Zuikaku with a thick diaper between her thighs, to the point where that padding was pushing out her dress and making it utterly impossible for her to hide any accidents or keep any sort of dignity, or the calm and collected white-haired Shoukaku wanting to avoid as many of the other babies as possible so they couldn't call special attention to her lack of a diaper. If they saw and they raised the alarm, then she would be stuffed in that crinkly and displeasing garment without her consent...

"I still can't believe she'd go along with what Akagi's trying to do..." Zuikaku muttered as she looked down at the tray packed full with her regular lunch. The only humiliating item on the menu was a childish carton of milk, which had been specifically added to her and her sister's diet. Because they apparently weren't growing up as much as the others, whatever that meant.

Shoukaku just slowly shook her head. "Our Admiral is... A curious sort." The white-haired Carrier muttered as she carefully picked up individual rice, a little nervous knot inside her stomach. "Despite the fact that Akagi returned to this base with a diaper soiled down to her knees, she took her in without batting an eye. Sometimes I worry if our Admiral is even worse than her..."

“Even if that’s the case, we’re still together, Shoukaku-nee!" Zuikaku smiled a bit as she shoveled a bit of rice into her mouth as well, sighing in relief. "As long as you're here, Shoukaku-nee, I'll keep fighting. Even if..." She blushed, squishing her thighs together to make her crinkly prison ring out. "Even if this is already around my waist."

Though Shoukaku felt a sense of relief washing over her just listening to her younger sister trying her best, it didn't take long before she felt a wave of discomfort weighing over her. She could tell exactly why too, it was the food she was eating. It was causing her stomach to twist and turn and want to expel it all straight into the back of her panties. Her expression began to waver ever slightly, one hand leaving her tray as she gently rubbed her stomach.

"Y-You too, Shoukaku-nee?" Zuikaku muttered, biting her lip a bit. "W-We can hold out! W-We just gotta eat as fast as we can, then we'll find a toilet. I'm sure there's one close by, and as long as you make it, it's fine. I'll figure something out if you stay dry!" Zuikaku did her very best to act positive. Even though she could feel the exact same kind of stomach-churning pain inside her belly.

Shoukaku nodded, as she looked down at her meal. It was mostly just a big bowl of rice and then that carton of milk. She had made sure to keep her order simple because she was wary that anything else might be spiked. So she dug in as fast as she could, swallowing chunk after chunk of that pile of rice.

As their hunger was being satiated, and both of the crane sisters were doing their best to try and avoid letting anything out despite the fact that their poor bowels had weakened so much already, they eventually both ran out of food. Not a single rice remained, and both of their milks had been downed to make sure that everything washed down properly. They could now head out and try to find a toilet, before either of them made a mess.

Shoukaku got up from her bed, having put the tray to the side for the time being, as she went straight for the door.

"S-Shoukaku-nee! I-It hurts! I-it hurts a lot!"

The white-haired crane whipped around to look towards her sister, who couldn't even get up. Her hand was on her stomach, and her body had collapsed back onto the bed. All while wet and consecutive *FRRRRT*s started to echo from the crinkly garment. Were they already this late?!

"H-Hurts... H-Hurts!" Zuikaku's attempts to remain strong had faded completely as she regressed into crying out like an oversized infant, tears running down her cheeks as she lost more and more control. Instead of rapidly farting, her gas turned into one long sustained *FRRRRRRRRRRRRT*, as all the gas inside her tummy and her bowels made way for something much more disgusting.

Shoukaku wanted to try and help her. She really did. But it was too late. Even though Zuikaku wanted her to just run on and try to save herself from making a mess in her panties, her legs grew too weak as she felt the gas slipping out from her cheeks with an equally wet and loud *BRAAAAAAAAAAAP*. Even just reaching down to touch her panties, she could feel how wet and how soaked they had gotten. There was no way that they'd be able to hold it in, whether because the toilet was too far away, or because the pain was too much to handle.

"D-Dun wanna poopy!" Zuikaku cried out in a much more childish tone as tears ran down her cheeks, sobbing and whining while the wettest mess she had ever made poured straight out of her hole and into the back of her cutesy diaper. It was so wet that it instantly soaked into the absorbent material, with the stickier stuff quickly being smushed against her rear with no chance of her wiping it off without any help.

Her older sister wasn't in a much better state. Shoukaku was forced to press her body up against the door leading out of their room as she fell victim to her own bowels growing weaker. She gradually fell onto her knees as the sound of her farts died down, and the sickening sound of something gross and wet poured out instead, the poor crane falling right down onto her ass and not only smushing out the brand new mess inside her panties, but letting it leak out over the sides leaving her sitting in a combined puddle and pile of her own waste.

It was humiliating. And to make matters worse, the mess wasn't done with just one piddly piece of poopy. Even as Shoukaku tried to press her hands against her stomach to stop herself from messing, the *BRAAAAP*s just quietly continued to pour out only to be switched out for the wet sensation of something foul slipping out from her loose hole. And right as it plopped out, it was mushed up against her cheeks with some of it forcing its way out the sides of her panties, just adding to the mess below her.

Zuikaku wasn't in a much better state. In between her constant sobbing and her cries to make it all stop, it just kept squeezing out of her hole. Sure, she was a lot cleaner and a lot less messy compared to her older sister, but the fact that she was messing a diaper made it that much worse for her current mental state.

"Make it stooooop! D-Dun wanna poopy lots!" Her mind had already taken such a beating by the constant pain, the endless stink, and the feeling of having it all pressed so compactly against her body. Zuikaku just wanted it to stop. She'd do anything to make this humiliating feeling inside her tummy go away, and the only thing she could do was look towards Shoukaku-nee to try and hope that she'd have an answer. She was so much stronger than her, after all.

Shoukaku trembled a bit as the tears started to pour down her cheeks. She couldn't endure this. And she completely understood how this had come to pass. "Akagi, you meanie..!" She muttered in anger under her breath. The milk that they had used to wash all of this down... It wasn't milk at all. It was just the infitting compound, given a new flavor to try and disguise it and make them think it was safe. She faintly recognized the original taste, but there was nothing to do now.

The longer she spent sitting in her own mess, the longer she felt it all pouring out of her, the longer she dwelled on her options at hand, the more she quietly understood. She had no options. She had made a big oopsie in her panties. She had proven herself to be little more than an overgrown infant. Just like Akagi had wanted her to be. She had told her from the moment she returned that she'd love to see everyone, especially the crane sisters, filling their diapers... And she had made it all come true. Because they were just like her. Big stinky babies who couldn't keep it held back.

"S-Shoukaku-nee..?" Zuikaku muttered, as her final *Frrrrrt...* quietly marked the end of her current accidents. There was nothing left inside her bowels, and the way that her diaper sagged as she slowly, painfully, managed to get off the bed and crawl towards her older sister showed just how much she had been unable to hold back. She was no better than any of the other babies, and she just... She just needed to see if her sister was any different.

Shoukaku slowly turned towards Zuikaku with her tears still rolling down her cheeks. One final wet fart left her broken hole, as she let a sad laugh leave her lips. "Zuikaku... We really are just big babies that need our diapers, aren't we..?" She had no strength left in her. The mess she had made on the floor, with stinky poopy piled around her inside that equally poopy puddle, was the last remnants of her strength.

Zuikaku nodded, as she gave her big sister a hug. And she sobbed as well, as the diaper between her thighs continued to squish and crinkle. Right now, she just wanted something to comfort her. Whether it was her older sister, or a dry nappy. Anything would be good right now, so they could just accept their status as big stinky babies…

Thus, the Crane Sisters became the Crappy Sisters. Known for their mutual massive messes, and their inability to stop it all. Another set of adorable babies that their Admiral adored.