Mare Training: Warhorse Drill
A vague dread of what was about to be done to her body tangled with a secret thrill, and her heart hammered in her chest. To that D-class hero of Sky City, the Horse Spirit posed a profound question.
Warhorse. The precise meaning of the word was still hazy to her, but Sonia pictured the magnificent steeds that once drew medieval chariots or a knight's carriage.
In the world the Horse Spirit came from, it was perfectly ordinary for a woman to undergo mare training—no, to be trained as a warhorse.
The values of that place held that serving one's master with pride as a warhorse was an honor beyond compare.
(A warhorse… that has to mean something combat-related, right? So… a soldier? Or a knight? If I'm meant to assist people like that… maybe armor?)
Armor… wouldn't it be, Spirit? Sturdy, gleaming armor.
Instead of the black leather restraint suit that clung to Sonia's body like a leotard, forged from some glistening magical force—surely a true warhorse would wear shining armor worthy of the name, something to protect her master and charge across the battlefield. Sonia offered what she considered a perfectly reasonable conclusion.
But the spirit's brown donkey ears drooped and fluttered with clear disappointment, and Sonia realized she had gotten it wrong.
"How unfortunate, Sonia! Truly unfortunate! For a warhorse, armor is merely the third most important element!"
The second, the Horse Spirit added, was a warhorse's proper mindset…
Second? That sounds like it should be the most important thing of all… There's something more important than mindset?
When Sonia voiced her doubt—that something could rank above a warhorse's mindset—the spirit snapped her donkey ears upright like antennae with a sharp Haaap…!
"Do not move from that spot, Sonia! Uhaaat…! Bam!"
It was the exact same spirited shout the Horse Spirit had bellowed before—when she had fitted Sonia with a black leather blindfold, a bright-red ball gag, and a leather belt that cinched her waist tight with her hands bound behind her back, dressing her in the black leotard-like training restraint suit with a cute little pong?!
Pssshhhh… pong?!
With a clean, crisp sound effect, every piece of restraint gear holding Sonia in the perfect mare posture dissolved in an instant into particles of light.
The bright-red ball gag, the leather blindfold that had blocked her vision, and the black leather training restraint suit that had bound both of her hands behind her back—everything vanished.
Ugh… this is a little… no, really embarrassing… Spirit…
Warm sunlight and a cool breeze touched bare skin directly. The moment the latex's pressure left her body, what washed over Sonia was not liberation but crushing anxiety and the shame of exposure.
At home, she sometimes—well, honestly, fairly often—wandered around in nothing but an unbuttoned white dress shirt in place of pajamas, not even wearing panties. Even so, she had never once stood completely naked in front of someone like this…
(No… that was when I was changing into the bodysuit… the situation was different… right?)
She had stripped down to nothing in front of her adventurer friend Luce while changing into the hero bodysuit the Association had issued her.
But that had only been part of getting dressed—she hadn't been standing there deliberately displaying her naked body—so it didn't count. Sonia piled up desperate excuses in her mind.
"Hmm… so that is how it is! Then let us begin! I shall bestow upon thee that which is far more important than a warhorse's equipment—or even a warhorse's mindset!"
With a thoroughly satisfied gaze, the Horse Spirit drifted up into the air and looked Sonia's completely naked body over from head to toe.
Even though the bright-red ball gag that had sealed her mouth had already been removed, Sonia did not break the posture she had just been taught—chest thrust proudly forward, standing tall on her tiptoes like a warhorse.
The ball gag was gone, yet Sonia had not even properly registered that the restraint suit and gag had "vanished," dissolving into powder. She drooled freely as she tried to convey what she wanted to say.
(Mmmh…! This girl… Sonia… those ample breasts, that well-conditioned body… she is a perfect raw gemstone for a warhorse! How truly unfortunate…)
Sonia had never been the athletic type, but the body tempered by D-class hero work put ordinary people to shame.
Those enormous breasts, grown just right for sturdy chest-protecting armor, and those solid thighs that, with a little more polishing, would become a warhorse's crushing kick capable of subduing an enemy in a single blow…
(And that is not all… this warhorse mindset of hers… she is an extraordinary talent—no, a warhorse prodigy! Which makes it all the more regrettable…)
The Horse Spirit desperately wished Sonia would cast aside her entire past as a human and swear to the heavens a warhorse's vow—to live out her life proudly serving a great master.
Alas, the world this girl Sonia lived in seemed far more familiar with those hard, speechless things called taxis than with the honorable warhorse.
(…I would love to entrust her with the privileges handed down through generations of warhorses… but that would be far too selfish a thought…)
There were two reasons the Horse Spirit was teaching Sonia these precious techniques without forcing a warhorse's vow upon her.
First: the moment the spirit returned to the spirit realm, the warhorse privileges would vanish forever from people's memories—so at least this gifted girl should inherit them.
Second: however slim the chance, if this girl happened to learn the warhorse privileges, someone might take an interest in the art of the warhorse. A faint hope, but a hope nonetheless.
(Truly… such a mindset is far too precious to waste… had she been born in another age, this girl might well have become the peerless first warhorse of one who ruled the world…)
What the Horse Spirit studied far more carefully than Sonia's solid thighs or the curves of her well-built body was her mindset.
The obedience that kept her voluntarily in a submissive posture even after the restraints were gone; the exceptional mental adaptability that converted shame into pleasure without a moment's delay—those were the true qualities of a supreme warhorse.
The spirit silently marveled, perfectly reframing Sonia's extreme masochistic tendencies as "a warhorse's innate talent."
Sway… bounce… bounce.
Still thrusting her chest forward with her hands clasped behind her back, Sonia conveyed her thoughts.
(Hmph! At this level, she would have stood head and shoulders above the countless mares who once lined up for warhorse training…)
The training gear that blocked human speech had long since been removed, and yet this trainee—adorably, deliberately—recognized this as warhorse training and kept her human words to an absolute minimum.
At first her embarrassment had been plain, but she slowly crouched down in an awkward squat, steeled herself… and then, as if proving she was a female fully qualified for warhorse training, thrust forward the pair of enormous, springily hanging breasts and crossed her wrists behind her waist.
"That is precisely the posture, Sonia! Keep it up and thou shalt claim every last login bonus—it will surely be of great help in that sturdy, healthy life of thine as a… hero, or adventurer, or whatever it is called! Now stand upon thy tiptoes and walk slowly!"
A… alright…! …Like this?
Supporting her full weight on her tiptoes, Sonia walked slowly forward like a model. The Horse Spirit pressed right up beside the mare who simply walked as instructed without looking back, examining her in detail.
The soft grass against her bare soles, the cool wind brushing every inch of bare skin, the heavy sway of her breasts and hips with every step—all of it registered with vivid clarity.
Every sensation constantly reminded her, I am completely naked right now, and a strange excitement—unbearable liberation mixed with shame sharp enough to tear her apart—began to soak the space between her thighs.
Though nothing bound them, her two hands stayed pressed firmly behind her waist as if lashed by an invisible cord of the mind this mare had tied upon herself. Her lips stayed sealed shut.
For now she was only a single mare with no master to serve—but if a master had been present, Sonia's mouth would have opened at once upon command. Left alone by a master, that closed mouth of a female warhorse would never open.
(…This is weird… this is really weird… walking naked through some strange field… mare training… ♥ Ah…! Th… this is all… that's what this is! This is a fated opportunity… a stat boost! It's just the training I need to acquire the privileges, so of course I'm enjoying it… I am… ♥)

Just as the spirit had taught her, following every detailed correction from the side, Sonia walked on with her chest thrust out proudly and boldly.
(…♡)
Not because she was forced to, but of her own will—deliberately displaying those springy breasts that bounced and settled right back into place…
Sonia had become a lewd exhibitionist, walking naked and proud across the wide open field. The nipples crowning those elastic breasts stiffened and rose in response to the cool air around them.