Miyuki, briefed on the flight spell, glanced at the newly adjusted CAD in her left hand. Smaller than her usual compact mobile-terminal CAD, it fit snugly in her palm. Unlike her general-purpose device, this was specialized.
"Ready for the test, Miyuki. Be careful. Psion usage is minimized, but it'll draw from you unless turned off," Tatsuya warned.
"Yes," Miyuki replied.
Her joy at Tatsuya's concern vanished as she focused. "Starting now."
Activating the CAD, she tackled one of magic's three great challenges: flight, long deemed impossible outside theory. With controlled tension, she flipped the switch. Psions were subtly drawn from her, barely noticeable unless focused on. The activation sequence loaded into her magic calculation area—remarkably small, efficient, and precise, as she'd been told. Even with her processing power, she could handle dozens simultaneously.
"(I'm floating… no, flying,)" Miyuki realized, rising near the basement ceiling, gravity's pull gone.
"(Is this what astronauts feel?)" she wondered, envying them yet pitying their need for heavy gear.
"Miyuki, is the continuous processing taxing?" Tatsuya called.
Snapped back, embarrassed for indulging in the sensation, she replied, "I'm fine. No headaches or fatigue."
Tatsuya nodded, satisfied. "Good. Now try slow horizontal movement. Once comfortable, speed up and fly freely."
"Understood."
Imagining horizontal motion, Miyuki moved as envisioned. The tiny activation sequence automatically adjusted gravity's vector, enabling seamless flight. "(This device chains magic via continuous activation. Variables carry over unless new inputs override. Brilliant, Onii-sama.)"
Her understanding reflected her expertise, but praising Tatsuya mattered more. Meanwhile, Tatsuya reviewed his design: "(The flight device pairs with Loop Cast. Loop Cast repeats identical spells by copying the activation sequence. This records spell timing, updating only variables for continuous casting, eliminating interference limits from stacked single-use spells.)"
"No interruptions in the magic?" he asked.
"None. The time-recorder function works perfectly, Onii-sama!" Miyuki confirmed.
Human skill alone couldn't sustain flight; mechanical aid was essential. "Onii-sama, can I fly freely now?"
"Go ahead, but it's tight in here. Be careful."
"Yes!"
Unleashing her restraint, Miyuki accelerated, weaving through the limited space with turns, spins, and flips. Her skirt fluttered, hair danced, and graceful curves flashed—enough to overwhelm any onlooker. Tatsuya, unfazed, watched.
"Onii-sama, join me?" she asked.
"There's only one device," he replied.
"Then I'll carry you!"
"That's a stretch, given our size difference."
"Then you carry me?"
Her eager expression suggested this was her goal. Tatsuya smiled wryly, declining gently. "Playing with a test-phase device isn't wise. No issues so far, but proper tests will happen at the lab."
"Alright… but we'll fly together someday?"
"Sure, someday."
Tatsuya's busy adjustments contrasted with Miyuki's dream of flying together, their expressions lively despite their differences. Their sibling bond—often called excessive—was undeniable. Tatsuya cherished Miyuki, and she adored him above all.
"Time to come down. Didn't you make tea?" Tatsuya said.
"Oh, right!" Recalling her purpose, Miyuki hurriedly descended.
The CAD Development Center of Four Leaves Technology (FLT), located two hours from Tatsuya and Miyuki's home by public transport, was remote. An electric bike could halve the trip, but bad weather ruled out riding together. For Tatsuya, familiar with the commute, the long journey was merely tedious.
"Miyuki?" he called.
"Yes, Onii-sama?" she replied.
"…Never mind."
"?"
Miyuki, puzzled by his hesitation, returned to her cheerful mood. Tatsuya had wondered why she was so upbeat despite the weather and distance but decided it wasn't worth asking since her mood was positive.
"Young master!" researchers swarmed as they entered a room at the facility. Unusually, Tatsuya, not Miyuki, was the focus. The "young master" nickname, once a sarcastic jab at his executive lineage, now reflected genuine respect for his potential leadership. Knowing their sincerity, Tatsuya couldn't ask them to stop.
"Pardon the intrusion. Where's Chief Ushiyama?" Tatsuya asked, mildly exasperated as Miyuki beamed, distracting the researchers.
"You called, Mister?" Ushiyama appeared.
"Sorry to bother you, Chief," Tatsuya said.
"No way! We're all your underlings here. Too much humility doesn't suit the boss," Ushiyama teased.
"You're employed by my father, not me…"
"Come on, Mr. Silver! It's an honor to work under you," Ushiyama insisted.
"If anything, you're the real top here, Mr. Taurus," Tatsuya countered.
FLT's CAD Development Division 3, home of the "Silver Model," was where the enigmatic genius Taurus Silver's identity was known. "Stop it. I'm no 'Mister' or 'Taurus.' I just helped a bit with your genius ideas. I'm only listed as a co-developer because I'm underage," Tatsuya said.
"Without your skills, Loop Cast wouldn't exist. My hardware knowledge pales compared to yours. Ideas are nothing without execution," Ushiyama replied, scratching his head in surrender.
"Enough! I can't outtalk you. So, what's today's visit for? Not just to see our faces, right?" Ushiyama asked.
Most researchers were men, making the lab less appealing for Tatsuya, though he noticed the admiring gazes of the few female researchers but avoided the topic. "Here, Ushiyama," he said, presenting the flight device.
"The flight spell?" Ushiyama asked.
"Your improvements made system tweaks easy," Tatsuya said.
The team understood: Ushiyama had refined Tatsuya's prototype. "Testing?" Ushiyama inquired.
"As usual, Miyuki and I. But we're not typical mages," Tatsuya noted.
Gasps filled the room. Overturning one of magic's three great challenges was monumental. "Tetsu, how many T-7 units do we have?" Ushiyama barked.
"Ten," Tetsu replied.
"Idiot! Why didn't you restock? Forget parts—full-copy the young master's system to all units! Hiro, get every tester! Vacation? Who cares! This is the flight spell—modern magic's history is changing!"
Amid the chaos, Miyuki stood calmly, smiling.
Testing ran overtime, not due to failure but because nine testers, switching to wireless from cables, started playing midair tag. "You're all idiots. Sustained magic isn't meant for long sessions," Ushiyama scolded.
No serious issues arose despite their recklessness. "Pay for your overtime yourselves," Ushiyama snapped, ignoring complaints. Turning to Tatsuya, he noticed his dissatisfaction. "Something bothering you?"
"The burden's still too high for regular mages," Tatsuya said.
"Of course. Normal mages' psions are nothing compared to you or the young lady," Ushiyama replied.
"We need to optimize the CAD's psion auto-draw scheme," Tatsuya said.
"Handle it in hardware, not software. A dedicated time-recorder circuit would help," Ushiyama suggested.
"I was about to propose the same," Tatsuya agreed, revealing his hardware prowess.
"Have you seen the director?" Ushiyama asked.
"No, he's busy…" Tatsuya trailed off.
"He's here today. I notified him," Ushiyama said.
The director, their biological father, was just that to Tatsuya and Miyuki—nothing more. "He doesn't neglect research, despite his schedule," Ushiyama added.
"I know. He doubled our budget, thanks to the young master," Ushiyama grinned.
As researchers nodded in gratitude, Tatsuya thought, "(Father's here? I'd rather avoid him, for Miyuki's sake.)" She despised him, and Tatsuya wanted to spare her the encounter. But fate, as always, was ironic…