Turning excess stimulation into affection.
When Kitahara Sota heard Agnes Tachyon's explanation, his brain momentarily froze.
Sis—no, you're my boss now—didn't you bother checking the side effects before taking this potion? And isn't this effect way too fantastical?!
He was already starting to regret it.
Had he known this was the potion's effect, he never would've gone so hard with the massage...
No, forget "going hard," he wouldn't have even touched her at all.
But now...
"You realize this feeling isn't real, right?" Kitahara asked stiffly, meeting Tachyon's openly affectionate gaze.
"Yes, I know." Tachyon nodded calmly, still smiling softly. "But does that matter? My liking for you is real right now, isn't it?"
"But the emotion itself is fake…"
"Love itself is subjective. Who decides what's fake and what's real?"
Besides, this wasn't completely artificial—it was more like an accelerated blooming of existing seeds. Even if the potion converted stimulation into affection, if her heart had truly been barren, any feelings would have evaporated instantly.
She tilted her head slightly, noticing the worry in his eyes. Playfully, she reached out and poked his stomach.
"Relax, my silly guinea pig. You don't have to be so worried—this effect isn't permanent. Otherwise, I'd definitely have noticed during earlier tests."
"…Then how long will it last?"
"Hm…maybe around half an hour more?" She gazed at him openly, affection undisguised. "So, for this remaining half-hour, could you perhaps indulge me and pretend to be my boyfriend?"
"No," Kitahara refused instantly.
Pretend to be lovers? Was she joking?
Putting aside the very real risk of faking it until it became reality, even if that didn't happen, once she regained her senses, she'd probably hunt him down mercilessly and drag him into the abyss alongside her.
"You just wait here for half an hour. I'll go check on Eclipse…"
That was Kitahara's safest solution to the current mess.
But…
As soon as Kitahara said this, Tachyon's cheerful expression immediately dimmed.
"You don't need to leave. If you don't want to pretend, it's fine. We can just continue with the care routine…I'm fine with it—"
"No."
"Just stay here until this state passes. I promise I won't try to use you as a test subject or anything else. I just want you nearby…"
"…No."
"I won't do anything. I just really don't want to be apart from you right now. Just half an hour, even if you sit far away from me. Please…"
"…No."
Though Tachyon's expression had turned pitiful, and her voice had grown desperate, Kitahara—after a brief hesitation—still refused.
Because no matter how convincing she appeared now, it was merely a side effect of the potion—not her true will.
More importantly, while Tachyon claimed she'd behave, he had no idea what she might actually do. Leaving was still the safest choice, both for him and for her.
So, after rejecting her again, Kitahara turned and began walking toward the door.
With every step he took, Tachyon's eyes grew dimmer, her expression visibly sinking into sadness. Her outstretched hand—reaching instinctively to hold him back—hesitated, trembling slightly before slowly pulling back.
She curled into herself, knees drawn up tight, head lowered.
Kitahara continued forward, but kept discreetly observing her, concerned she might do something rash. Seeing her like this, he couldn't help but feel a pang of guilt.
But that was all he could do—feel guilty.
As pitiable as she looked, he knew clearly these emotions were artificial side effects. Acting on them would only complicate things further. Leaving remained the best option.
With a heavy sigh, Kitahara finally unlocked the door, hand gripping the doorknob.
Yet he couldn't press down.
Because behind him, soft sobbing began.
"I knew it…Guinea Pig-kun really hates me, doesn't he?"
"I'm selfish, spoiled, troublesome, and terrible at racing…"
"I can't even take care of myself without help, yet I always act arrogant…"
"Alright, alright. Fine, I won't leave."
Kitahara knew she was probably exaggerating on purpose, but hearing her spiral into self-loathing like this was too much. Reluctantly, he turned around—and realized something shocking.
Tachyon's despair wasn't an act.
She was curled up on the bed, eyes red from crying. Seeing him turn around, she quickly averted her gaze and took several shaky breaths, clearly trying to control her emotions—but failing. Soon, quiet sobs filled the room again.
Kitahara felt utterly lost.
I know it's fake, and you know it's fake, so why can't we both just sit tight for half an hour? Where's your rationality when I need it most?
Oh, right. He'd pushed her too hard earlier, and her heightened affection was probably stomping all over her rationality now.
Sigh.
Unable to bear it any longer, Kitahara sighed deeply and trudged back, sitting beside her again.
"Alright, alright, I'll stay here with you until the half-hour passes. Stop crying, okay?"
"…I'm not crying," Tachyon mumbled into her knees.
"Yes, yes, of course you aren't."
Kitahara had no idea how to handle this, so he settled for his usual resigned acceptance.
After exchanging a few brief words, they both fell silent again.
So…how exactly did things end up like this?
Even Tachyon herself wasn't sure.
At first, discovering him had been purely accidental. Curious, she'd investigated out of amusement.
Back then, she'd been confident in her abilities as a trainer and hadn't even considered needing help. He was simply an intriguing guinea pig whose reputation she could borrow to step onto the racetrack.
But gradually, something shifted.
Initially, Tachyon never thought about love or affection, dismissing such sentiments as pointless distractions compared to her experiments. But after meeting him, everything changed.
He effortlessly tore apart her seemingly perfect theoretical plans, mercilessly exposed her flaws, shattered her self-confidence, and laid bare the harsh reality of her potential future.
Any other Uma Musume might've thrown a tantrum, rejecting the truth. But Tachyon quickly understood his words were undeniable.
There wasn't a single Uma Musume who didn't yearn to run, to chase victory. Yet the cruel truth lay right in front of her, forcing acceptance.
Then, the clipboard tapped lightly against her head, and his voice spoke gently:
"Anyway, it's troublesome, but I'll figure something out for you."
What a strange person, she'd thought at the time.
He wasn't even her tantou, disliked trouble, and she'd clearly stated she was fine as is. So why insist on complicating things?
If she thought about it further, her initial despair was entirely his fault.
First he destroyed her confidence, revealed the painful truth—and then, when she was lost in the darkness, he extended a hand, promising salvation.
Wasn't that just a little too cruel?
If previously she'd toyed with Tokai Teio during their little competition over the chair out of mere curiosity, from the moment he tapped her head a second time, she truly viewed him as her guinea pig-kun.
But that had only been the beginning.
He carried too many mysteries—so many that, during experiments, her mind often drifted, pondering his secrets.
Eventually, she'd even set her research aside, circling around him instead, desperate to satiate her curiosity.
Curiosity, fascination—they often heralded the start of deeper feelings. Especially since Tachyon, due to her personality, lacked real friends. She might not have cared at first, but once he entered her life, others gradually followed.
Even someone as independent as her eventually discovered she needed connection.
Kitahara was different. On the surface, he might seem wary of her—but upon closer inspection, he wasn't scared of her specifically. He simply disliked unnecessary trouble.
Uniquely, he treated her normally—not like some eccentric weirdo. He complained endlessly, yes, but was always there whenever she truly needed him.
Even her frequent attempts to drug him were met only with exasperation, never genuine anger or restrictions.
Tachyon loved this feeling, craved it even.
And though Kitahara had brought Agnes Digital to care for her, ironically, Digital's overly clingy affection forced Tachyon to become more self-sufficient.
Buying food, washing clothes—especially her underwear—although she remained clumsy, she had genuinely improved.
Furthermore, after joining Kitahara's team, Tachyon finally started interacting with others more naturally. Her world no longer revolved solely around experiments, becoming brighter, more lively.
Even her research had benefited from becoming his assistant trainer—she'd gathered invaluable data, progressing faster than ever, correcting past mistakes she'd overlooked.
Slowly, imperceptibly, her life became filled entirely by him.
After the preliminary race, Tachyon hadn't truly resented him. She'd simply realized certain uncomfortable truths, becoming confused about how to face him. His subsequent absence allowed her to recover slightly, but she still stubbornly refused to fully confront her feelings.
But now, everything became clear.
She genuinely liked him.
This wasn't just the potion's side effect—it was undeniable truth.
The potion merely amplified existing affection into an overwhelming burst of bravery. When it wore off, she'd probably revert to her previous, cowardly self.
Yet regardless of the potion's reality, she knew one thing for certain:
She couldn't bear losing her guinea pig-kun, let alone being hated by him.
Yet the potion only strengthened affection, not courage or desire. Its overpowering effect prevented her from harboring harmful thoughts, leaving her helpless to obey his wishes.
Facing his departure, she couldn't resist—only weep silently, feeling immense sorrow.
But unbeknownst to her, this sorrow perfectly struck Kitahara's weakness.
So he returned.
So she stopped crying.
Quietly shifting closer, she gathered her courage and leaned towards him, whispering softly into his ear with a mysterious tenderness:
"Guinea Pig-kun… How about taking this chance…to make me yours?"