Chapter 1: I Turned Into a Fluffy, Adorable Gray-Haired Horse Girl

"Ughhh… I wish I could turn into a fluffy, adorable gray-haired horse girl and make some mediocre guy fall head over heels for me…"

Looking back, maybe it all started with that dumb, otaku-esque delusion of mine.

—Uma Musume. A fictional phenomenon where real-life racehorses are anthropomorphized into cute girls. Just describing it makes it sound ridiculous.

Without going into too much detail, the gist of these horse girls' stories is that, through various experiences, they deepen their bonds with their human partners—trainers.

As an ordinary working adult, I found myself drawn to this fictional world. And, well… I also kinda wanted to be one of those horse girls and mess with some guy’s head.

Let’s be real—it’s a creepy gender-bending fantasy. But can you blame me? Who hasn’t dreamed of becoming a cute girl and using their looks to toy with someone’s heart?

"I wanna be a legit adorable horse girl and totally lead my trainer on~"

After tweeting that into the void, I tossed my phone aside and turned off the lights. Just another nonsensical, over-the-top rant from a terminally online otaku. A pathetic attempt to escape reality by whining into the digital abyss. Hell, tons of people post stuff like this.

—Which is exactly why…

I never thought it’d actually come true.

By now, I’d already forgotten about that dumb tweet. Cozy in the darkness, I let my consciousness melt away into a light, dreamless sleep.

---

When I woke up, an unfamiliar ceiling stretched above me.

Did I crash at a friend’s place after drinking too much? Trying to shield myself from the chilly air, I burrowed deeper under the covers. I fumbled around blindly for my phone, but it was nowhere to be found.

"...Huh?"

My mornings always start with mindless scrolling and checking my daily quests in Uma Musume Pretty Derby. Skipping that routine put me in a bad mood. Grumbling, I kicked off the blankets—

—And that’s when I noticed something was off.

(…Wait, since when do I have white hair?)

A flash of white at the edge of my vision. I grabbed a strand—soft, silky, and definitely attached to my head. Not just a few strands, either. It was long. And completely white. What the hell?! I’m only in my mid-20s! Ahaha… guess I’m officially an old man now…

Overcome with despair, I flopped back onto the bed. Ugh… at least the warmth of the blankets is comforting.

……

But as I pulled the covers over my head, I realized something else.

Wait, since when are my hands… tiny?

I stared at my own palm in disbelief. No way this was a guy’s hand. It was pale, smooth, almost translucent. No bony knuckles—just soft, delicate fingers with neatly trimmed nails. Like… a girl’s hand.

…Okay, this is way too weird.

White hair doesn’t just grow overnight. Hands don’t just shrink. And my memories of how I got here are fuzzy at best. To put it lightly—this is bad.

My brain finally registered the severity of the situation, and all drowsiness vanished. I kicked off the blankets and tumbled out of bed.

"Ow—!"

My voice was definitely a girl’s. The pajamas I was wearing were definitely women’s. And across the room, some random girl was sleeping in another bed.

My brain is about to blue-screen.

In a panic, I scrambled across the floor—until my eyes landed on a hand mirror resting on the desk.

—A horrible, earth-shattering, world-ending premonition hit me.

Trembling, I picked it up… and looked.

"——!?"

Staring back at me was a stunningly beautiful horse girl, her eyes wide with shock. She—no, I—had a short, fluffy bob of gray hair, amethyst-colored eyes, a petite nose, and soft, pink lips that looked downright squishable—

HOLY SHIT I’M CUTE?!

Even my shocked expression was lethally adorable. What the hell?! Since when am I this cute?! Wait, no—since when is being cute this overwhelming?! And hey, these horse ears—are they mine now? I reached up (probably around Rice Shower-sized) and gave one a tentative poke.

"Ohhh… I see."

The texture was kinda like a cat or rabbit’s ear. The only difference? Since they were attached to my head, it tickled. The gray fur was super fluffy too. Oh, and there’s cartilage in there…

"Ohhhh shiiit—"

I’ve gotta say, my ability to adapt to insane situations is unnatural. One second, I was mesmerized by my own beauty—the next, I was making a bunch of dumb faces into the hand mirror.

Angry face. Smiling face. Deadpan face. Crying face. (Well, I couldn’t actually cry on command, but still.) Damn, I’m too freaking cute.

And my body—!? Hell yeah.

…Wait, are these big? Like, actually big?

"Apollo-chan… what are you doing?"

"!?"

While I was busy checking myself out, the girl sleeping across the room suddenly spoke up. Who are you? And who the hell is "Apollo-chan"?

This was bad. Scratch that—none of this made any sense!

"I—uh, I mean, I was just, y’know… getting ready for school! Ahaha!"

I tried to play it off, but the chestnut-haired horse girl rubbing her eyes just tilted her head.

"Apollo-chan… it’s Saturday. No school today."

…Ah.

First words out of my mouth, and I’d already dug my own grave.

Who was I? Where was I? I’d blurted out school like an idiot, but I had no clue what that even meant here.

…Honestly? Maybe I should just come clean. If the lies were gonna pile up anyway, it’d be easier to rip off the bandage now.

"…Look, I’m sorry. I—uh, I don’t remember anything."

"Y-you don’t… remember?"

"…Nope."

"Are you serious? Did some shady doctor stick you with a weird needle or something?"

"I don’t even know that much…"

I forced myself to sound girly while spilling everything.

"Hmmmm… I see."

My roommate—Green Teatan—rested her chin on her hand.

"So, you’ve got serious amnesia… and you’re super lost, huh?"

"Yeah… pretty much."

"You okay after all that?"

"I’ll manage. Sorry for dumping this on you."

"Don’t even worry about it!"

Turns out, my name was Apollo Rainbow. This place was the Japan Horse Girl Training Center Academy—or Tosen for short. And apparently, Green Teatan and I were both middle schoolers here. Oh, and it was April, right after the entrance ceremony.

…Yeah, I remembered none of that.

According to Green Teatan, the old me—Apollo Rainbow—had enrolled in Tosen with the goal of becoming "the strongest stayer." So, if Past Me was to be believed, I had some natural talent for long-distance races. For now, my goal would just be: "Become the ultimate stayer!"

…Of course, now that I was this adorable horse girl, I also kinda wanted to mess with some trainer’s head.

Anyway, there was this thing coming up—the Selection Race. And hey, I’d made it into Central Tosen, which was apparently a big deal. In horse-racing terms, only a tiny fraction of racehorses ever debut at the central tracks, right? So that meant I—Apollo Rainbow—was basically elite-tier. Ahaha, I’ll be fine!

---

…Yeah, I was an idiot. A colossal idiot.

"AND THE WINNER IS—SPECIAL WEEK!! She dominates the Selection Race, leaving the competition in the dust!"

Yep. I’d gotten matched against Spe-chan. Oh, and turns out I was in the same generation as some of the strongest horse girls ever. I’d been so busy adjusting to my new life that I hadn’t even considered who my peers were.

Special Week. Grass Wonder. El Condor Pasa. Seiun Sky. King Halo…

Short-distance, long-distance, even dirt races—this generation was stacked with monsters.

"Guh—hack…! They’re all… too fast…!"

I collapsed onto the turf, wiping away rivers of sweat. Oh, and my placement? Dead. Last.

Not that it was surprising. I’d somehow forgotten every ounce of a horse girl’s competitive instincts, and I had no idea how to run properly. But still… watching Special Week surrounded by trainers made my chest ache.

Damn it.

I wanted to be strong. I wanted to win, to get showered with praise. I wanted to toy with some trainer’s heart!

—But if you didn’t place well in the Selection Race, you didn’t even get a trainer. No trainer meant no debut races. And Tosen Academy? It was a cutthroat world where only the strongest thrived.

…I’d forgotten that.

In the games, winning was easy. You didn’t even have to try—just tap a screen, and boom, unstoppable horse girl. But here? The heat radiating off the other girls, their sheer will to win—I’d never felt anything like it before.

This… wasn’t a world where half-assing would cut it.

"Haah… haah…!"

Special Week was a given, but even the 2nd and 3rd-place finishers were getting scouted. Fewer trainers than Spe-chan, sure—but their talent was undeniable.

…I was jealous.

I wanted to be the one they fought over. I wanted to leave them all in the dust.

But that… wasn’t happening.

"So… this is my best…?"

No. This couldn’t be my best. I had room to grow—had to.

Let’s be real—the odds were stacked against me from the start. "Hey, you just woke up in a horse girl’s body—go sprint your heart out!" Not making excuses, but damn, I was thrown into the deep end.

But—I did have one advantage.

I knew the future.

Every major race—the Satsuki Sho, the Derby, the Kikuka Sho, even the senior classics—I remembered all their results. Every rival’s strengths, weaknesses, racing styles… Thank god for the internet.

If raw talent wasn’t enough, I’d outthink them. Just like Seiun Sky did.

…Except, uh, problem: I was probably way less talented than Seiun Sky.

Pretty sure she once said, "I don’t have as much natural talent as the others." Yeah, well, I had even less. Compared to her, Apollo Rainbow was basically background fodder—the kind that gets wiped out in debut races.

Funny how I’d gained a new respect for those "mob" horse girls now. They weren’t even in the original world’s history. No guaranteed strength, no legacy—just sheer, grinding effort.

---

"Special Week, run the Japanese Derby with me!"

"No, I’ll make you the strongest horse girl!"

"With me—"

"I can—"

Trainers swarmed Spe-chan, already arguing over her post-debut career.

…Right. To them, the Selection Race was just a formality.

(…Tch.)

I’ll make them see me.

I bit my lip. Something hot and fierce ignited in my chest.

Back when I played Uma Musume Pretty Derby, I’d get pissed when my horse girls lost debut races. I’d delete saves on the spot, rage at every defeat.

Skipped every story event. Ignored conditions, running styles, even their dreams—just shoved them into races to farm fans. All I cared about was high rolls. How many virtual girls had I erased for that?

The words I’d spat were ugly. "Stop getting blocked by mobs." "Don’t lose by a nose." "Better stats." "More fans." "Low rolls." "High rolls—"

But this wasn’t a game.

No resets. No alarm clocks. Just reality—raw and unrelenting.

My chest burned. The heat spread, swallowing me whole, until it became an unstoppable need.

Was I just gonna lose like this?

Hell no.

I owed it to Apollo Rainbow—the girl whose body I’d taken. She’d enrolled here to become the strongest stayer. At the very least, I had to win one long-distance G1 for her.

Something inside me shifted.

I’d tried my hardest today—and still got dead last. Even ignoring Special Week, I’d been crushed.

And it pissed me off.

"Screw this!"

No fighting spirit? Scared of sprinting full-tilt? Shut up! I’d break through it all! This pathetic pride of mine? I’d use it as fuel!

"Special Week—!"

Special Week—Japan’s ace, the one who’d beaten Europe’s champion, Mondjue (Blowyay in this world).

But now? I had a target.

I’d surpass her. Become the ultimate stayer. No matter what.

Clenching my fists, I gritted my teeth. To overtake girls who trained every day, I’d have to work twice as hard.

Rumors said most trainerless horse girls quit Tosen Academy. In this world, racing was everything.

So I had to win.

No—I would win.

I hate hard work.

But after tasting this burning humiliation—this pitiful, worthless feeling—even I know there’s no choice but to grind.

…Maybe this is what it means to be a horse girl. That raw, instinctive hunger to win.

"…Time to head back."

I trudged toward the dorm, pulling out my UmaPhone. The calendar app glared back—three more Selection Races scheduled.

"…Only three shots left."

Races every two weeks. Then, Make Debut.

Meaning: I had less than two months to get strong enough to attract a trainer. Fail, and I’d be expelled.

…Brutal.

How was I supposed to improve alone? I didn’t even know my own racing style. How could I win like this?

My only hope was dodging monsters like Special Week and Grass Wonder, scraping victories in the mob-filled lower brackets.

"Long road ahead… and pitch-black, too."

If I did stage a comeback, it’d be far from now. Stayers peak late—summer, after the classics.

Step one: Win one Selection Race. Get a trainer.Step two: Grind to Open Class.Step three: Finally challenge Spe-chan’s generation.

The more I planned, the more it felt like counting unhatched eggs.

But I won’t quit.

It’ll be long. It’ll suck. But for Apollo Rainbow’s dream—and my dream of messing with some trainer’s heart—I’ll do it!

I slapped my cheeks to hype myself up.

Too hard.

Later, my face swelled into a perfect handprint.