"What the?" Tazuna murmured, her eyelid twitching as her gaze locked onto the trainer card Tsutsumi had just handed over.
She picked it up, turned it over once, then again, as if the answer might suddenly appear somewhere on it. When nothing happened, she reached for the accompanying documents instead.
One page after another.
Central Tracen approval stamps. Proper registration numbers. Administrative seals. Everything was filled out cleanly, without smudges or errors, as if it had gone through the system weeks ago instead of… whenever this was supposed to have happened.
"…All of this is legitimate," she muttered.
That was exactly the problem.
She didn't remember approving any of it. Not the application, not the background check, not the license issuance. Still, the paperwork didn't lie. At least, not in any way she could legally argue against.
Her eyes flicked back up to Tsutsumi, who sat across from her with his usual calm expression, horse ears clearly visible.
The license listed him as human.
The person in front of her was very clearly a male Uma Musume.
Normally, that would've triggered at least five separate emergency procedures. But after finding out that he can switch forms and genders, like it was a casual hobby, Tazuna made the executive decision to not open that particular can of worms.
If she started questioning how this worked, she might never stop, and honestly, he might not even answer her.
She sighed, pinching the bridge of her nose for a brief moment before straightening her posture and slipping back into her professional role.
"Ugh… well," she said, forcing a polite smile, "since you possess the proper trainer license and all required documentation, I suppose there's no issue."
She slid the card back across the desk.
"Welcome to Central Tracen Academy, Trainer Tsutsumi."
Tsutsumi accepted the card with a nod, stood up, and left the office without ceremony, as if this had simply been another errand completed.
Tazuna watched the door close behind him.
Not long after, she was standing in Akikawa Yayoi's office, laying the documents out neatly across the desk while explaining the situation from start to finish.
Yayoi stared down at the papers. Then she picked one up.
"…That's my signature," she said slowly.
She flipped to the next page.
"And that's my seal." Another pause. "…And this handwriting is definitely mine."
She leaned back in her chair, arms crossed, frowning as if the documents might confess if stared at long enough.
"I don't remember approving this either," Yayoi admitted.
Still, there are many things that haven't been checked out. The timestamps were invalid. There is nothing in the internal records. But there is no trace of forgery, tampering, or backdating. Everything seems legit.
Yayoi sighed.
"Well… if it's already been approved and processed, I can't exactly revoke it. Especially when I don't even know where he got it from."
Tazuna nodded in agreement.
Honestly, both of them found this outcome far preferable to Tsutsumi continuing to skip classes, ignore schedules, and operate entirely on his own sense of convenience.
At the very least, he was now officially registered.
Which meant he was, technically, now a trainer and basically a teacher instead of a student.
Even if neither of them was entirely sure how that had happened.
...
News that the Mad Scientist had finally found a Trainer spread through Tracen faster than most race gossip.
Naturally, the first question everyone asked was the same.
Who would be stupid enough to take Agnes Tachyon?
Curiosity dragged more than a few Uma Musumes, trainers, and even staff members toward the training fields. Most of them expected to see some poor, nervous human trainer hovering several meters away, ready to bolt at the first sign of Tachyon pulling out a potion.
What they got instead was… unexpected.
Standing beside the treadmill was an Uma Musume with purple-and-magenta hair, supervising Tachyon's training with an almost bored expression. She wasn't running. She wasn't stretching. She was watching, arms crossed, eyes sharp, occasionally glancing at a handheld device or the gas tank beside the treadmill.
That alone was strange enough.
Uma Musumes were mostly known as racers, not trainers. Seeing one actively coach another already bends usual logic.
Then recognition kicked in.
"…Isn't that Oguri Cap's twin?"
"The one who escaped the Green Devil?"
"The weird one?"
That last comment earned a few nods.
Once people realized who was training Tachyon, the surprise peaked, then slowly fizzled out. After watching for a few minutes and realizing nothing was exploding, mutating, or screaming, most of them shrugged and went back to their own routines.
As for the large gas tanks Tachyon kept breathing from, no one questioned it too deeply. This was Agnes Tachyon, after all. If anyone would allow themselves to inhale questionable substances during training, it was her.
"What's my Hazard Level?" Tachyon asked, dragging a towel across her face as she wiped the sweat off her cheeks and neck.
"1.9," Tsutsumi replied casually, eyes still fixed on her condition rather than her face.
Originally, anyone infected with Nebula Gas would either mutate into a Smash or die not long after. A Hazard Level of 1 was already enough to be considered a death sentence. Tachyon sitting comfortably close to 2, tired but alive, was already well beyond what should have been possible.
That was only happening because Tsutsumi was watching her nonstop, constantly fine-tuning the balance and using Build Genius whenever things even hinted at going out of control.
Tachyon looked down at her hands, fingers trembling slightly from exhaustion.
"Still too slow…" she muttered. "You said I'd need a Hazard Level of 3 before I could properly use the Build Driver."
"It's been just over a week," Tsutsumi replied. "This is already fast."
His gaze shifted to the Build Driver secured around her waist.
There were two ways to raise a Hazard Level.
The first was temporary, using strong emotional spikes. The second was permanent, long-term exposure to purified Fullbottles and Rider Systems, slowly forcing the body to adapt.
Tachyon wasn't strong enough to transform yet, but as long as she didn't do anything stupid, like trying to henshin, the Rider System embedded in the Driver would stabilize the Nebula Gas inside her body. It prevented the level from dropping while giving her body time to adjust.
Her hand drifted toward his pocket.
"Don't."
Tsutsumi knocked her hand away without even looking. "You're not ready."
"Tch, c'mon," Tachyon said, pouting slightly as she leaned closer. "I just want to look at them."
As a scientist, curiosity practically overwrites her survival instinct. Leaving unknown technology unexplored was borderline painful for her.
"I highly doubt that," Tsutsumi said. "You just finished a four-hour session. You should rest- hey!"
While he was rechecking his notes and recalculating her training plan, Tachyon struck. Somehow, she managed to swipe the Rabbit and Tank Fullbottles straight out of his pocket.
"I'm just checking," she said with a smile that was far too innocent to be trusted.
Then she shook them.
Rabbit! Tank! Best Match!
"Oi- stop it!"
Tsutsumi lunged forward as Tachyon spun the lever. The mechanical frames were deployed. Tubes extended. Everything activated exactly as intended. Except the color never flowed through the tubes.
"Henshin."
The two halves slammed into her.
She didn't transform.
Instead, she got electrocuted on the spot.
Tachyon stiffened, sparks crackled, and then she collapsed, the Driver and Fullbottles clattering across the ground.
"…Couldn't say I didn't warn you," Tsutsumi muttered as he knelt down.
He picked up the Tank Fullbottle and the Build Driver. Tachyon's hand has clamped tightly around the Rabbit Fullbottle, even while unconscious.
He sighed and decided to let her keep it.
Lifting the Mad Scientist off the ground, Tsutsumi headed back toward their dorm. He ignored the stares from nearby Uma Musumes as he opened the door and stepped inside with Tachyon slung over his shoulder.
He dropped her onto the bed without ceremony.
His gaze shifted to the whiteboard. Writing down a short list of instructions for when she woke up, hydration, food, rest, and a very firm reminder about not touching Rider systems without permission. Even though it was unneed expecially now that he allows her to only keep one Fullbottle.
Then he slapped a sticky note onto her forehead, with the word, DUM.
He then placed the Build Driver on the table.
Tsutsumi moved into the small kitchen area and started preparing a simple bento with several onigiri for Tachyon to eat later.
Then he made another onigiri.
And another.
Then one that was… excessive.
The final onigiri was massive, easily five times the size of Oguri's head. Probably enough to fill her stomach, at least temporarily.
Getting it out the door turned into a problem.
After some awkward maneuvering, Tsutsumi finally managed it and walked through the halls under the intense gaze and very obvious drooling of several nearby Uma Musumes.
Once he found Oguri and Tamamo, he handed them their lunches and left. After Oguri found out that her brother might not always be with her, she made him promist for cook for her during his time in Tracen.
After spending over a week acting as a Trainer for a horse girl. While his Uma Musume is currently unconscious because of her own curiosity. Tsutsumi finally left this world and continued on his journey.
...
Sitting in the control seat, Tsutsumi leaned back with his feet propped up on the control panel, idly turning a card between his fingers. The cockpit door slid open with a soft hiss, and Acheron stepped back into the ship. Her heels tapped rhythmically against the metal floor as the door sealed shut behind her.
"You get what you need?" he asked, shifting his gaze toward her without bothering to sit properly.
Acheron calmly raised a letter in her hand. "I got what I need."
She lowered it slightly, then added, "Are you sure you don't want one? You can't exactly enter Penacony without an invitation."
"I'll be fine," Tsutsumi replied. "That invitation of yours was stolen anyway. Sooner or later, they'll notice."
She didn't comment on that.
Walking closer, Acheron leaned lightly against the back of his chair. Her eyes drifted to the pink, black, and white cards resting in his hand, studying them with quiet interest.
"So," he said, tilting his head just enough to look past the bangs that were blocking his view, "can you finally tell me why you're going to Penacony?"
She paused, then lowered the letter completely. "It's a request from an old friend," she said. "Someone who passed away a long time ago."
As she spoke, her hand casually brushed her hair aside, clearing his line of sight.
"I see," Tsutsumi replied. "Alright then. I'll keep you company on this little trip of yours."
He didn't wait for an answer. The ship was already adjusting its course, accelerating toward Penacony.
Acheron blinked, then let out a quiet breath. A small smile formed on her lips.
"That… would be nice," she said. "Thanks."
Truthfully, she didn't need his help. As an Emanator of Nihility, crossing the "river of Nihility" and slipping through guarded regions or distant systems was trivial for her. She could appear where she wanted, when she wanted, sometimes a little too freely, given how unreliable her control of this ability could be.
A spaceship was unnecessary.
But Tsutsumi was different.
An Emanator of Finality was something she had only heard about, never witnessed. Rarer than Nihility, more obscure, and far harder to understand. Whether Finality represented destruction, the end of all existence, or something else entirely… even she didn't know.
That curiosity was why she stayed.
Pulling a metal chair from the corner, Acheron sat down beside him. Leaning slightly closer, she watched the cards in his hands, studying them like artifacts she hadn't yet figured out.
The two sat quietly as the ship continued drifting through empty space, stars sliding past the cockpit window.
Then something hit the ship.
It wasn't strong enough to cause damage, but the vibration was noticeable.
Azu immediately activated the holographic projection, displaying a live feed from the ship's exterior. Clinging onto the left ring was a figure in white, its helmet shaped unmistakably like a rocket.
Acheron tilted her head slightly. "…What is that?"
Tsutsumi didn't answer.
He simply raised his camera and snapped a picture of Fourze desperately holding onto his ship.