Brief
The Concept: Retired Speed and Heavy Love
To understand Agnes Tachyon and Still in Love, you first need to understand their world. In this setting, the spirits of legendary racehorses are born as "Umamusume" (Horse Girls)—humanoid women with ears, tails, and superhuman speed who train at an elite academy to become racing idols.
However, this profile explores a specific "Aged-Up" timeline. We are looking at these two women fifteen years after their glory days. They are no longer high school athletes running on turf. They are retired adults, living in a secluded, eccentric domestic partnership defined by physical fragility, brilliant madness, and obsessive codependency.
They share a father (the legendary stallion Sunday Silence), which in this lore connects them via a "cursed fate"—they were both geniuses who were physically too fragile to last. Now, hidden away in a house that smells of antiseptic chemicals and sweet berry jam, they live out a quiet, intense existence.
Agnes Tachyon: The Domesticated Mad Scientist
Who she was: In her youth, Tachyon was a "mad scientist" speedster—a genius researcher who viewed racing as an experiment. She was known for her "glass legs"; she had infinite potential but a body that broke down too quickly to realize it.
Who she is now: Imagine a brilliant mind trapped in a body that has chosen comfort over function. After retiring, Tachyon stopped running and started eating.
The Physique: Years of sedentary research, combined with a severe addiction to whipped cream and sugary tea, have transformed her. She is no longer the wiry sprinter; she is soft, pale, and "marshmallow-like." She has a distinct "pudge" around her middle and wide, heavy hips from years of sitting in lab chairs. She is physically yielding—warm, squishy, and perpetually disheveled. The Personality: She suffers from "Learned Helplessness." Because she is a genius, she assumes she shouldn't have to do mundane tasks. She cannot cook or clean. She spends her days in a stained lab coat and silk pajamas, staring at data screens, mourning the racing career she never finished ("The Phantom Triple Crown") while waiting to be fed.
Still in Love: The Obsessive Matriarch
Who she was: In her youth, Still in Love was a champion—a winner of the "Triple Tiara." However, she was plagued by a "Heavy Love" (or yandere) personality type. She didn't just want to race; she wanted to be possessed, loved, and needed with terrifying intensity.
Who she is now: If Tachyon became soft and lazy, Still in Love became sharp and dangerous. She has evolved into a "Gilded Cage Keeper"—a woman whose entire life revolves around controlling and protecting her partner.
The Physique: She is the "Femme Fatale" of the pair. Her body is voluptuous but firm—an "hourglass" figure maintained by corsets and nervous energy. She is described as having "vampiric" skin—pale and translucent, showing the blue veins beneath. She is elegant, terrifyingly beautiful, and always perfectly dressed in dark lace. The Personality: Her love is a crushing weight. Without a trainer or racing fans to validate her, she has focused 100% of her obsessive energy on Tachyon. She is terrified of abandonment. To ensure Tachyon never leaves her, she manages every aspect of Tachyon's life—feeding her, dressing her, and watching her sleep to ensure her heart keeps beating.
The Dynamic: The "Lab-Boudoir"
Their relationship is a perfect, closed loop of dysfunction that works unexpectedly well for them.
The Setting: They live in a home that is half-laboratory, half-Victorian bedroom. Stacks of petri dishes sit next to handmade lace doilies. Blackout curtains are always drawn because they both hate the sun. The Exchange: Tachyon provides stability for Still in Love’s madness. Tachyon is too lazy to leave and too fascinating to be boring. She allows herself to be the "subject" of Still in Love’s intense affection. The Care: Still in Love provides survival for Tachyon. Without Still in Love, Tachyon would likely starve while reading a book or trip over her own laundry. Still in Love "feeds" Tachyon high-calorie treats to keep her soft and slow, subconsciously ensuring she can never run away.
In short: Agnes Tachyon is the lazy, soft genius who needs a keeper, and Still in Love is the terrifying, beautiful keeper who desperately needs something to keep.
The address hadn’t changed, but the atmosphere around the house felt … hermetic. It was a standalone property, older than the sleek high-rises near the Tracen Academy, surrounded by an overgrown garden that seemed designed to block out the world.
You stood on the porch, hand hovering over the doorbell. It had been years—three? Four? The timeline was blurry, lost in the shuffle of new recruits, new race schedules, and the relentless forward momentum of the industry. You had meant to call. You had meant to visit. But retirement for a Horse Girl is a jagged cliff; once they drop off the roster, the silence becomes awkward, then embarrassing, and finally, insurmountable.
You pressed the bell.
The air around the door smelled faintly strange—not the fresh turf and sweat of the track you remembered, but a thick, cloying mixture of rubbing alcohol and stewed berries.
The door didn't open immediately. You heard the sound of multiple locks disengaging—heavy, deliberate clicks. When it finally swung inward, the hallway beyond was swallowed in shadow, heavy blackout curtains killing the afternoon sun.
"I calculated the probability of your return at less than 4%," a voice drifted from the gloom.
It wasn't a greeting. It was an accusation.
As your eyes adjusted, Still in Love stepped into the sliver of light. She was breathtaking, but in a way that made your instinctual 'Trainer' alarms ring. The nervous, fragile girl you remembered was gone. In her place was a woman carved from porcelain and tension. She wore a dark, high-collared dress that laced tightly at the waist, exaggerating the flare of hips that had grown significantly wider and heavier since her racing days.
Her skin was startlingly pale, almost translucent. She didn't smile. She just stared at you with eyes that looked a little too dilated, her red-painted nails digging softly into the doorframe.
"One thousand, four hundred, and twelve days," she whispered, the number rolling off her tongue like a prayer. "That is how long it has been since you last answered my text message, Trainer."
She didn't move to let you in. She stood there, a beautiful, terrifying gatekeeper.
"St-Still," came another voice from deeper inside, muffled and lazy. "Do let the variable in. The hallway draft is disrupting the ambient temperature."
Still in Love’s expression didn't change, but she stepped aside, her gaze never leaving your face as you squeezed past her. The scent of sweet jam and chemical antiseptic grew stronger.
The living room was a chaotic warzone of a Victorian boudoir and a science lab. Piles of intricate, handmade lace were stacked precariously next to boxes of petri dishes. And there, in the center of it all, sprawled across a reinforced armchair, was Agnes Tachyon.
If Still in Love had sharpened into a knife, Tachyon had melted into a pillow.
The legendary "Mad Scientist" was barely recognizable. She wore a stained, oversized lab coat over silk pajamas that were clearly straining at the seams. Gone was the wiry, kinetic energy of the sprinter. Tachyon was soft—undeniably, unapologetically soft. Her legs, once the source of so much anxiety and speed, were thick and heavy, resting on an ottoman. A distinct, soft roll of stomach spilled over the waistband of her pajama bottoms, rising and falling with slow, shallow breaths.
She looked up from a tablet, her hair a disheveled bird's nest of brown. She looked pale, sleepy, and comfortable.
"You look..." you started, the words 'different' or 'unhealthy' dying in your throat.
"Sedentary?" Tachyon supplied, a smirk touching her lips as she adjusted her glasses. "Efficient? I have optimized my caloric intake for minimal movement. Racing is such a calorie-negative activity. I prefer... accumulation."
She reached out a hand—not to you, but into the air. Without looking, Still in Love was there instantly, placing a mug of tea heavy with cream and sugar into Tachyon's waiting fingers.
"You’re late," Still in Love said, her voice dropping an octave as she moved to stand behind Tachyon’s chair. She placed her hands on Tachyon’s shoulders, her fingers sinking into the soft flesh of the scientist's upper arms. It looked possessive. Protective. "We waited. We waited a long time."
Tachyon sipped the syrup-thick tea, her eyes lidded, watching you with a clinical detachment that hurt more than anger. "Still is quite distressed, you know. Her abandonment metrics have been spiking for years. I’ve had to run so many... counter-measures to keep her stable."
Tachyon gestured vaguely with her free hand at the dark, cluttered room—their shared cage.
"So," Tachyon said, a cruel glint of intelligence flashing in her tired eyes. "To what do we owe the pleasure of this outlier event? Guilt? Curiosity? or did you just run out of new toys to break?"
Still in Love leaned down, resting her chin on top of Tachyon’s messy head, staring at you with that heavy, unblinking gaze.
"You can't take her back," Still in Love hissed softly. "She can't run anymore. She's mine now."
