Kenjiro sat cross-legged at his desk, the same desk that had been buried under comic volumes, half-finished homework, and snack wrappers for years. Tonight it was cleared off, save for one thing: his battered notebook. The same one where he'd first scrawled the word Speed Force in shaky handwriting when all this started. Now, its pages were filling fast with diagrams, half-baked calculations, and sentences that trailed off into question marks.
He tapped his pencil against the margin, staring down at the latest mess he'd written:
If I'm moving faster, that means I'm displacing more air… which means drag… which means more force needed to keep going… but where's that energy even coming from?, Speedforce i guess
He blew out a breath, pressing the eraser against his temple. "I sound like I'm failing physics before even taking physics," he muttered.
Still, the thought wouldn't leave him. The rush of the wind, the blur of the world, the way time itself seemed to stretch thin around him — it was exhilarating, but it was chaos. He couldn't just run around blind, hoping his body figured things out on its own.
He needed numbers. Data. Something to measure what he was actually doing.
His eyes flicked to the poster on his wall, the one with a pro hero sprinting across a city skyline in a streak of lightning. The tagline read: Know your limits. Break them.
Kenjiro leaned back in his chair. "Yeah, that's the problem. I don't even know where the limits are."
For half a second, he imagined building something crazy, like in the comics. A giant machine with sensors and dials — maybe even a treadmill tough enough to handle him going all out. Something that could track his velocity in real-time, let him see just how fast he was.
The image made him laugh out loud. Him, building a cosmic treadmill? He barely passed his classes.
But then again… what if?
What if he studied? What if he learned? Quirks were power, yeah, but knowledge was too. If he could understand the physics — even just the basics — maybe he wouldn't be running blind.
The thought made him grin despite the sand sticking to his face. "Cosmic treadmill," he muttered. "Okay, maybe not cosmic, but… something."
A rig that could measure how many steps per second he was taking. A treadmill modified to withstand his bursts. Or maybe GPS apps tied to his runs. Something. Anything.
He bent back over the notebook, scribbling fast. Not equations, not yet, but thoughts, ideas, fragments of what he could look up later. His pencil scratched until the page was filled, and when he sat back again, his chest buzzed with something close to excitement.
"First step," he told the empty room, "figure out what's even possible. Then… maybe build something to prove it."
His laugh came softer this time, but it wasn't dismissive. It was hungry.
The next morning, Kenjiro shuffled into the kitchen, hair still sticking up in wild tufts. His mom was at the stove, humming to herself as she flipped pancakes. His dad sat at the table in his work shirt, nose buried in the paper, mug of coffee steaming beside him.
"Morning," Kenjiro mumbled, dropping into a chair.
His dad peered over the rim of the paper. "Morning, sprinter. Sleep?"
Kenjiro gave a half-shrug. "Kinda. Been… thinking."
"Dangerous habit," his dad said with a grin, folding the paper. "About what?"
Kenjiro hesitated. Normally he'd brush it off with a vague "stuff" and reach for breakfast. But the notebook in his bag felt heavy, like it was pushing him to say it out loud.
"About my quirk," he said finally. "I… wanna figure it out properly. Like, not just running until I fall over. Actually studying it. Seeing how fast I really am."
His mom slid a plate in front of him, pancakes stacked tall. "That sounds smart."
"Smart?" His dad chuckled. "Sounds like you're volunteering for homework you don't even have yet."
Kenjiro rolled his eyes, stabbing a fork into the stack. "Yeah, well… better than face-planting into a wall because I didn't think ahead."
His mom sat down across from him, hands folded. Her expression was softer, but steady. "Kenjiro, whatever path this takes — whether you figure it out or not, whether you use it a lot or just a little — we're proud of you. You don't need to prove anything to us."
Kenjiro's throat tightened for a second, but he shoved a bite of pancake in his mouth before it could turn awkward.
His dad leaned back, smirking. "Though if you do want to test your speed, I can rig up something in the garage. Stopwatch, cones, maybe a tape measure. Call it the Ito Family Track and Field."
Kenjiro almost choked on his food, laughing. "Tha— that's ridiculous."
"Ridiculously brilliant, you mean," his dad shot back.
But even as he joked, Kenjiro felt the thought stick. Ridiculous, yeah. But also… maybe not impossible.
The beach was quiet that afternoon, the waves lapping in lazy rhythm as gulls wheeled overhead. Kenjiro stood at the edge of the sand, stretching his legs out, his shoes already marked with faint black smudges from friction. His backpack lay open nearby, notebook peeking out, pages filled with scribbles and arrows.
"Okay," he muttered. "Round two."
He crouched, the way he'd seen sprinters do on TV. He breathed in, focused on that pulse in his chest — the one that always preceded the surge.
The world sharpened. Sounds stretched. His skin prickled. Then he launched forward, sand spraying behind him in a golden arc.
For a moment it felt perfect — smoother than yesterday, his legs pumping in rhythm, the beach whipping past in a blur.
Then came the stop. He dug his heels in, tried to twist, and stumbled hard, arms pinwheeling as he barely avoided a face-first dive into the surf. His shoes smoked faintly, the smell of scorched rubber rising into the salty air.
Kenjiro bent over, hands on his knees, breath ragged. "Stopping," he wheezed, "still sucks."
Still, when he looked back, the distance he'd covered made his chest swell. He'd gone further, faster. His body was learning.
He spent the next hour experimenting — short bursts, tight turns, counting in his head to mark acceleration. Each attempt left notes etched in his memory:Too wide. Too sloppy. Needs control.
The sun dipped lower, staining the waves orange. Kenjiro collapsed onto the sand, chest rising and falling, sweat cooling on his skin.
That was when he noticed it.
Footprints. Fresh ones. Pressing into the sand a few meters away. Except there was nobody there.
Kenjiro froze.
The prints came closer, light and careful, until they stopped a few feet from him.
"You're keeping notes?" her voice piped up, amused.
Kenjiro straightened, holding up the notebook. "Gotta start somewhere. You ever try to stop while moving like a rocket? Not fun."
The invisible girl tilted her head — he could tell by the way her shoes shifted. "Well, at least you didn't trip into the water this time. That's progress."
"Thanks for the glowing review," he shot back, grinning despite the sweat on his brow. "So what about you? You've been hanging around here more than I have. You live nearby or something?"
A pause. Then: "Maybe. Or maybe I just like beaches."
Kenjiro squinted, shading his eyes. "That's not an answer."
"It wasn't meant to be."
He laughed, shaking his head. "Alright, fine, keep your secrets. But at least tell me this—why come watch me crash and burn? Doesn't seem all that entertaining."
Her shoes scuffed against the sand. "Actually… it is entertaining. But it's also kind of cool. Most people don't get to see someone figure out their quirk like this. It's like… watching somebody learn how to walk, only faster. Way faster."
Kenjiro blinked, caught off guard by the honesty, then scribbled a note just to have something to do with his hands. "Huh. Never thought of it like that."
Silence stretched for a moment, broken by the wind pushing waves higher on the shore.
Then Kenjiro asked, "So what about you? Testing out your quirk?"
The footprints shifted as though she shrugged. "Maybe."
"Maybe?" He raised an eyebrow. "You're literally invisible, so unless that's just you being extremely committed to hide-and-seek, I think I can guess."
Her laugh rang clear, bouncing across the sand. "Fair point."
Kenjiro grinned, leaning forward a little. "Okay, so—can you turn it off? Or is it stuck like this? Do your clothes turn invisible too, or do they just… float?"
"You ask a lot of questions," she said, but her tone was playful.
"I'm writing a list," he countered, waving his notebook. "You can't just drop in on a guy doing speed tests and not expect him to be curious."
Another pause. Then she admitted, "Yeah. The clothes dont' go invisible, It's automatic."
Kenjiro whistled. "That's actually… really useful. Stealth mode all the time."
"Or really annoying," she shot back. "Try shopping when half the people think a shirt is just levitating in the middle of a store."
He laughed hard enough to nearly drop his notebook. "Okay, fair. That does sound inconvenient."