Chapter Text
She was the biggest umamusume fan in the entire universe, her and her Trainer, obviously. Their dream was to meet every single uma alive, in every region, at every racecourse, so she could worship and simp from a safe distance. That’s how it had to be. She wasn’t worthy of breathing the same air as her oshis, girls like King Halo, Opera O, Special Week, Teio, goddesses every one of them. The best she could do was run beside them, prove herself on the same track, and maybe get a close-up blast of their sweat if fate was kind.
And if she happened to take the long way around the track to stare at their asses… that was training! Deep focus! Core conditioning! If she happened to walk on tiptoe past the dorms at night imagining rarepairs and fanfic scenarios so hot she nearly short-circuited, that was just… creative inspiration! She was fine! Totally fine.
Anyway, today was a crisis. A glorious, horny, reality-warping crisis.
She’d just had a con haul with her Trainer, digital booth, merch sales, doujin giveaways, sketch commissions, same old hustle. She made sure no one noticed that her “assorted print files” folder that definitely wasn't 90% drawings of King Halo’s big sweaty ass and armpits.
She held herself together, she only drooled a little, it was fine. Drooling and simping aside, this run collected something new: a bunch of doujinshi featuring her favorite umas, SFW and… not. Opera’s romance anthology. Special Week’s bubbly rippers. A Vodka x Daiwa Yuri…
But one of the doujinshi in the stack caught her eye in a weird way. Like it radiated a taboo aura. Extreme tag warning. She normally avoided those because she was easily influenced, her brain chemistry rewired at the slightest kink like some perverted AI built to absorb degeneracy forever. Still, curiosity was a cursed drug. She was too easily swayed by the opinion of similar-minded people.
Back in her dorm, Tachyon was gone, luckily or…not so lucky? She cracked open the doujinshi. She couldn’t help herself from taking a peek at reading them.
And… it was filth. Blatant, wet, shameless filth. Fart kinks. Piss kinks. Full-on scat scenes. Idol-tier uma girls absolutely desecrating toilets and each other’s laps, shining from sweat and shame, bending over to unleash sewers, clenching their thighs as they squatted into buckets, moaning from relief and humiliation. The art was beautiful. Breathtaking, even. Whoever drew this loved their subject matter. Every detail was weirdly respectful despite being depraved. It was hot. It was wrong. It made her heart pound so hard she thought she might faint.
She couldn’t stop reading.
It was gross, weird, one had to think what was the point of it. Though, the more she read, the more she couldn’t pull her eyes away, the more taboo it had all felt, the more she wanted to indulge. Her oshis, THIS vulnerable, this raw! This gross– it looped around to all being hot again. At least, that’s what she felt at the time.
She had to find more.
She had to do more research.
So she did what any sound-minded otaku would do: she broke into Tachyon’s bookshelf. She couldn’t help herself, she had gotten far too obsessed with the tags once she got into the logistics of it. (Which she hopes she doesn’t find out about, she’d commit harakiri on the spot!!! Please forgive her!) She dug past race data and running form diagrams until she found an entire section on umamusume biology, digestive capacity, hydration demands, fiber uptake, specialized toilets. She copied entire passages into her phone, hands shaking, half turned on and half terrified Tachyon would catch her and drive a scalpel into her stomach for defiling the sanctity of science.
The info was mind-blowing. Of course a completely different biology would mean different digestion. More muscle, more stamina, more nutrients, more fuel. But she hadn’t realized how drastic it was. Umamusume bowels were basically engines, ready to handle ridiculous volumes of food, water, supplements, race fuel. They produced crazy amounts of waste, thick and constant. Tracen had special reinforced toilets for this. The janitors literally filed reports about clogs the size of sandbags and smells that left them crying into hazmat masks. The girls joked about “bombing bathrooms” but it was true, they destroyed plumbing like it was a national sport.
Umamusume produced a lot of waste and could hold a lot of food in their bodies. At Tracen, and most uma-themed locations, there are special toilets specifically designed for Umamusume as they produce so much waste from their bodies that they regularly clog toilets, it defied the natural laws of physics.
Of course she’d know, she was still a umamusume. Sure, not as impressive as her oshis but…still one nonetheless. Digital did know that the maintenance crews and janitors would complain often about the clogged toilets and how often the umamusume toilets would be bombed and wrecked with the scents of horse girls but…Digital wouldn’t complain if it were her, personally. It would be an honor.
Her mind spiraled into fantasies. Her idols, desperate, clutching their stomachs backstage. King Halo sniffing and pretending she wasn’t about to burst. Special Week sweating through her shorts, cheeks clenched, tail stiff, ready to blow. Oguri Cap quietly excusing herself, smile serene, face pale, then absolutely destroying a stall. She wanted nosefulls of that stench, wanted to watch them struggle, wanted to hold the door shut as they swore and hammered, wanted to fan them while they sat on toilets sobbing with relief. She went feral just imagining it.
Getting off track. Again.
After doing a decent amount of research she was far too down the rabbit hole of this kink that she had to experience in reality to see if it was as amazing as it truly had seemed in the doujinshi she had read. That brings her to now.
She needed to see it in person. For research. She was tired of watching, dreaming and imagining. She needed a taste of the real thing.
On her day off from training, she fixated on Special Week. Sweet, earnest, gluttonous Special Week. She knew the girl hit that one restaurant religiously, the one with the endless buffet and the “Champion” crown she proudly wore after eating twelve meals. Digital followed her there, camera in hand, brain dissolving into yuri soup as Spe’s cheeks bulged from stuffing dumplings in whole.
Spe demolished stacks of plates. Piles. Mountains. Digital lost count. After two hours, Special Week waddled out, cheeks flushed, stomach so round and tight it looked like it might pop. She patted it, winced, and muttered to herself.
“Mmngh… I’m glad Trainer went home, I have to use the bathroom so bad…”
Digital’s knees nearly buckled. This was it. She tracked Spe at a distance on the path back to Tracen, heart pounding, thighs pressed together, the whole world reduced to her oshi’s backside. The way her hips swayed as she walked. The weight of that stuffed belly jostling. Her tail flicking and curling anxiously.
Special Week froze suddenly, legs clamped together. “No no no…”
The tail twitched upright. Digital barely had time to inhale before—
PRBBBBBBBBBBBBBBBBBBBBPPPPPPT!
A sonic boom of pure ass. A bassy, explosive, bubbling blast that shook the trees and echoed off the buildings. She took the hit head-on, full force to the face. It was so loud it rattled her teeth. It was so heavy with sulfur and unprocessed meat that she gagged instantly. The stench was brutal, thick, meaty. It was the smell of a gut pushed beyond reason, curry, steak fat, protein shakes, all blending into a noxious cloud that burned her eyes.
She staggered forward, one hand over her heart, the other pressed between her legs, breathing hard through her mouth because her nose was useless. Spe let out a weak whimper, cheeks scarlet, rubbing her gut. Digital wanted to scream hallelujah. This was perfection. Her oshi was farting for real, desperate, panicked, raw. It was filthier than the doujin. It was better than anything she’d ever seen. She was shaking. She could smell it still, sticky and hot, wrapped around her hair and skin. It was so intimate she almost cried.
She was so turned on it hurt.
Special Week was still frozen, her hands clapped over her mouth, her face a brilliant, horrified shade of scarlet. The fart had been a monster, a true sonic boom of pure ass that had left her own ears ringing. She scanned the empty path, her eyes wide with a panic that was quickly turning into profound, gut-wrenching embarrassment.
No one was there. Not a soul. She let out a long, shaky sigh of relief that was almost another fart. “Phew... Nobody heard that…”
Digital, crouched behind a bush, was having a religious experience. She was breathing in lungfuls of that thick, meaty air, her entire body trembling. Her oshi is relieved nobody heard her filth! My perfect, pure oshi is a secret sinner! This was too good. This was bliss. She was so turned on she thought her phone might melt in her hand.
Special Week, having reassured herself, started walking again, her pace now a frantic, determined waddle. Every step was a frantic race against her own bowels. The gurgles from her stomach were getting louder, more frantic. Gggglllloooorrrrggggllle... blorp... gggggllllooorrrrggggllle! It was a symphony of impending doom.
She reached Tracen and practically sprinted down the hall. She ignored the strange looks, her face a mask of desperate need. She burst into the main bathroom, her eyes darting for an empty stall. Finding one, she dove inside, slamming and locking the door behind her.
Digital was right behind her, a silent, predatory shadow. She slipped into the adjacent stall, her heart hammering against her ribs so hard she thought it might explode. She carefully positioned her phone over the top of the stall wall, angling the camera lens down. The screen lit up, showing a perfect view of Special Week's legs, her shorts around her ankles, and her glorious, large ass descending onto the toilet.
This was it. The main event.
The moment Special Week's ass cheeks hit the porcelain, she let out a shuddering moan of pure relief. Then, the bombing began.
FRRRRPPPT!
A loud, explosive fart shook the very walls of the stall. The sound was deep and angry, a blast of pure pressure being released. The smell, even through the barrier of the stall, was immediate. It was a hundred times worse than the fart outside. It was a concentrated cloud of pure, unadulterated digestive rot, thick with the smell of curry, cheap beer, and something that could only be described as 'agony.'
Digital had to bite her lip to keep from making a sound. Her own panties were soaked, a river of her own arousal soaking through the fabric. She watched, mesmerized, as Spe's body tensed again.
PRRPRPFPTPRPRPRPRRRPPT!
Another colossal fart, this one wetter, more of a splattering sound. It was followed by the sound everyone in Tracen feared: the ker-plonk of a massive log hitting the water.
Digital’s eyes were glued to her phone screen. She could see Spe’s legs trembling, her muscles straining. Another log, this one even thicker, dropped with a heavy KERSPLOP that sent a splash of water back up to hit her ass. Special Week let out a little cry, half-pain, half-relief.
The shitting was relentless. It was a continuous, explosive evacuation. Log after log after log, each one seemingly larger and more dense than the last. The sounds were a disgusting, percussive symphony. KER-SPLAT. PLUD-SPLUD. KER-PLOP. The air in the bathroom was now a visible, toxic haze. It was the smell of a hundred blocked toilets all crying out at once.
Digital felt like she was going to pass out from a combination of lust and lack of oxygen. She was recording this. She was living this. Her hand was shaking so badly the camera footage was jittery, but it didn't matter. This was the single greatest moment of her entire life. She wanted to frame this video. She wanted to make it her phone's background. She wanted to build a shrine to this moment.
Finally, after what felt like an eternity, the bombardment slowed. A few last, wet farts echoed in the bowl. Pfffft-blllrrrt... Prrrt... Then, silence. A moment of peace.
Digital was panting, her body slick with sweat. She had to get out of here. She had to go back to her room and immediately, immediately masturbate to this footage until she passed out.
Spe let out a long, shuddering sigh that seemed to come from the very depths of her soul. Digital, frozen in the next stall, heard the soft pat-pat-pat of a hand on a relieved stomach.
“Whew…” Spe murmured to herself, her voice soft and a little dazed. “Okay… okay, that’s better.” There was a moment of blessed silence. Then, a tiny, almost shy addition. “Mmn… I think I’m a little hungry again, though…”
Digital had to clamp both hands over her mouth to stop the hysterical giggle that was trying to burst out. She just destroyed a toilet with the force of a volcanic eruption and her first thought is a snack! She’s perfect!
The squeak of the toilet seat shifting signaled Spe standing up. Digital heard the soft rustle of clothing being adjusted. Then, the definitive click of the flush handle.
Clunk-gurgle…
The toilet made a wet, choking sound. The water in the bowl sloshed ominously but didn’t drain. Instead, the water level rose slightly, lapping at the brim, revealing the dark, monstrous mass lurking just beneath the surface.
“Eh?” Special Week’s voice was small. “No, no, no…”
She tried again, more frantically this time. The result was the same, but worse. A foul, bubbling sound erupted as the water, unable to descend, churned the contents of the bowl. A fresh, hot wave of that incredible, gut-wrenching stench flooded the stall, so potent it made Digital’s eyes water. She could taste it on the air, a thick, rancid soup of everything Special Week had consumed.
A panicked whimper escaped Spe. “I-I broke it! I broke the reinforced toilet! They’re going to be so mad! The janitors will know it was me!”
Digital heard the stall door unlock and fly open. Spe’s frantic footsteps pattered across the tile floor, and then the main bathroom door slammed shut, leaving Digital in profound, sacred silence.
For a full minute, Digital didn’t move. She just breathed, inhaling the holy atmosphere her oshi had left behind. Then, with the reverence of a pilgrim entering a shrine, she slowly unlocked her own stall and crept out.
The bathroom was empty. She tiptoed to Spe’s stall and pushed the door open.
The sight that greeted her was more beautiful than any trophy, any winner’s circle photo. The toilet was a disaster zone. It was clogged to the absolute brim with a mountainous, lumpy pile of shit. The logs were immense, thick as her forearm, tangled together in a dense, dark brown heap. The water was a murky, disgusting broth, and the smell… the smell was a physical presence, a heavy, humid fog of pure Special Week. It was the most intimate thing Digital had ever witnessed.
Her hands shook as she raised her phone. Click. Click. Zoom in. Click. She took picture after picture, documenting every glorious angle of the destruction. The sheer scale of it. The proof of her oshi’s incredible, disgusting power. This was a secret treasure more valuable than any limited-edition merch.
She fled the bathroom, a blissful, manic grin on her face, the toxic air clinging to her clothes like a blessing. She practically floated back to her dorm, her mind a whirlwind of ecstatic filth.
She collapsed onto her bed, pulling up the photos and the video. She was euphoric. But as the initial high faded, a cold, practical thought wormed its way in.
Her Trainer.
They shared everything. They were a team, united in their simping. This was the biggest discovery of their lives, a whole new dimension to their worship. But this… this was different. This was a level of depravity that went beyond buying doujins. This was real. This was invasive. This was a kink so niche, so taboo, that admitting it felt like social suicide. Could she ever look her Trainer in the eye after confessing she got off to secretly recorded videos of their favorite uma shitting?
She stared at the ceiling, one hand idly drifting between her legs, the other still clutching her phone filled with contraband. Should she share this newfound heaven with the only person who might understand? Or should she take this delicious, rotten secret to her grave?
She didn’t know. But as she replayed the video, the sound of that first, earth-shattering fart filling her ears, she knew one thing for certain: her life would never, ever be the same again.