Chapter 4 : The Silent Standoff 沈黙の対立

The late afternoon sun filtered softly through cherry blossoms, scattering pale pink petals over moss-covered stones near the I-house. A gentle spring breeze stirred young leaves, carrying a distant birdsong and the quiet murmur of the Uji River. Beneath the sweetness in the air lingered the sharp, earthy scent of wet grass and soil—a silent promise of rain hovering close. Above, dark clouds gathered slowly, heavy and brooding, as if the sky hesitated before its coming downpour.

I hurried toward the math research club, but something in the fragile stillness stopped me among the falling petals. There lay a lone crow, its wing twisted beneath a ruffle of dusty feathers. Its glossy black eye opened once—slow, tired—as if burdened by years too heavy for one so small.

A sudden, urgent caw broke the quiet. Another crow swooped down—dark, muscular, fierce. It landed with a flutter, wings beating like warning drums, its sharp cries cutting through the thickening air.

The injured bird hissed weakly, pressing back, but the other crow was relentless, pecking without mercy. A chill ran through me, as if the delicate beauty of this place had fractured, revealing a small, cruel truth beneath. In that moment, I felt the fragile weight of silent battles. Hoshino-sensei’s words echoed faintly in my mind, sending a shiver through me.

I took a slow breath and crouched, extending my hand gently.

“Hey… it’s alright. I’m not going to hurt you.”

The injured crow’s wary eyes met mine—wide, curious, and hesitant, but it stayed. The aggressor let out one last piercing caw before retreating into the trees, leaving silence behind.

I reached out cautiously, careful not to startle. The small bird nestled against my palms, its fragile chest rising and falling in a faint, irregular rhythm—warmth barely perceptible through my fingers. Its glossy eye blinked once, meeting mine in a silence deeper than words.

I rose slowly, the thickening breeze threading through my sleeves, brushing my skin, carrying with it the scent of damp earth and leaves. The world around me seemed suddenly vast and hushed—the soft rustle of leaves, a distant birdcall, the quiet pulse beneath my hands.

For a long moment, I held this fragile weight close, neither moving nor speaking—simply letting the quiet breath of life speak for itself.

I removed my blazer gently, wrapping the tiny body with care so as not to press on the injured wing. Holding the crow close, I made my way back to the sanctuary of the clubroom.

—

“Hello, Kanzaki! What are you holding?!” came a chorus of warm welcomes.

“Welcome back, Kanzaki-kun”

“You’re late, Kanzaki !!”

“Sorry, everyone. I brought an uninvited guest”

Rain began to patter softly against the windows.

Inside, the clubroom remained warm and calm. I lowered myself to the floor and laid the crow down on a soft cloth. Its uneven breaths were faint but steady beneath my fingers.

Hoshino-sensei and Kisaragi were quick to respond. Hoshino-sensei offered a bottle of saline solution, and Kisaragi handed me clean cloths and bandages.

I carefully examined the wing. The twist was evident, and there was a shallow, raw wound near the joint, crusted with dirt and dried blood. Drawing from what I’d learned working at the clinic, I dampened the cloth with saline.

“Okay, little one, let’s clean you up,”

Delicately, I wiped away dirt and dried blood, revealing tender skin beneath. There was no deep gash, but enough to require attention to prevent infection.

I bandaged the injured wing loosely, then fashioned a small splint from a couple of wooden sticks I found nearby to immobilize it. It was an improvised fix, but stable enough to prevent further damage until proper veterinary care.

The crow remained still, its glossy eye reflecting quiet trust or maybe just exhaustion. I carefully wrapped it in a spare cloth, shielding it from sudden movements and the encroaching chill of the evening air. Uchida brought over a cardboard box, and Kisaragi padded it gently with soft cloth.

“Don’t worry, everyone. I’ll contact the vet advisor from the biology department,” Hoshino said.

Everyone felt a quiet relief. Kisaragi and Uchida sighed in relief, the tension easing.

“I was agonizing over what to do next, as expected of our Hoshino sama”

Outside, the rain intensified, and thick clouds darkened the sky further, the steady patter striking the windowpanes like a quiet drum.

It's rather rare for Kyoto to have heavy rain in April…

Kisaragi staring the window as well, perhaps she was pondering the same thought

Hoshino sensei cleared her throat softly.

“Well, since we’re all here… I want to thank each of you for your hard work. The effort you put into preparing for the IMO selection was truly remarkable. You pushed yourselves beyond what I expected.”

Her words carried a weight heavier than their polite phrasing. We all knew what lay beneath.

The three of us focused on her, the silence stretching just enough to let tension thread through the room.

“The selection process was extremely competitive this year, with many hard-working students across the region. After careful review of the final exams and camp performances, I have the results for our team.”

My heartbeat thudded loud enough to drown the rain outside. Sweat prickled at my temples.

“Kisaragi and Kanzaki, congratulations. You have both been selected to represent Japan at the upcoming International Mathematical Olympiad. Your dedication and perseverance made this well deserved.”

My heart seemed to catch and then release all at once. The weight of uncertainty lifted from my shoulders.

I shifted my glance quickly to Uchida. Our eyes met briefly, a silent exchange of unspoken words. Kisaragi and I shared a steady nod—an acknowledgment of what this meant for all of us.

Hoshino sensei continued with delicate care, “Uchida, I know how much this meant to you. Please understand that this decision does not diminish your immense talent or the hard work you put in. The competition was incredibly tight this year. Sometimes selections come down to mere points or a strength sought by the selectors. You have a brilliant future ahead; this is only the beginning of your journey.”

Uchida’s head bowed slightly, her fingers curling lightly in her lap. Her lips pressed together, and then, almost imperceptibly, tears traced a silent path down her cheek.

Hoshino sensei moved closer and gently wrapped her arms around Uchida, her hand resting delicately on her head, her fingers stroking softly along her hairline.

The fragile dam broke. Uchida’s shoulders trembled as a quiet sob escaped, swelling slowly into a soft, wrenching cry.

“Oh you…Remember, being part of this club means we learn and grow together. There are many more opportunities ahead. Uchida, your dedication here has been invaluable, and we all believe deeply in your potential.”

“I know you have tried very hard…” She continued to stroke Uchida’s hair gently, her touch light as a whisper. Beneath her composed exterior, a faint shimmer caught in her eyes.

Kisaragi shifted, stepping closer with careful steps, hesitating as if unsure how best to reach out, “I’ll be here for you… Uchida-san…” speaks shyly.

I placed my hand gently on Uchida’s trembling shoulder. “Yeah... We’ll always be here to support you.”

After a short moment of quiet sobbing, Uchida’s breath became more steady. She pulled herself upright, shielding the fragile ache behind a practiced, quiet smile –a perfect facade.

“Co-congratulations…! Akari-chan, Kanzaki-kun… I knew you two would make it ! We need a proper celebration for this achievement! Let's have a small toast! I’ll order some food for us!” Her eyes were still swollen.

We all looked at each other, with a gentle smile. Kisaragi looked particularly excited and motivated.

Knock knock—the door opened.

“This is the math research club, right? Hoshino-sensei asked me to come over.”

“Yeah, thanks for coming, sensei. I have an injured crow here, please take a look.” I bowed softly.

“No problem. It’s part of my job.”

Kisaragi guided the advisor to the cardboard box for diagnosis. Uchida called the school cafeteria to order some sushi boxes.

The vet advisor carefully examined the crow’s wing and its body, gently testing its range of motion.

“Extraordinary! The first-aid is perfectly done. The bandage and splint are stable and should give the wing the support it needs to heal,” nodding approvingly.

“The wound isn’t deep, but we’ll want to monitor it closely to prevent infection. I have brought some antiseptic ointment, depending on how it improves, antibiotics might be necessary.”

He glanced up at us with a smile. “It’s clear you all care a lot for this little patient. This kind of dedication gives the animal a better chance of recovery.”

I’m relieved. “Thank you for coming all the way, we wanted to do everything right until you could check on it”

“You’ve done great work and correct with limited resources. The box reduced the sensitivity and stress significantly, and the calm atmosphere here is a plus”

“I just hope it's not allergic to mathematics”

We all giggled softly in sync.

Turning toward Uchida, whose eyes were still swollen and tired. “Taking care of others takes patience and heart. It's okay now, don’t worry.”

There’s a small misunderstanding. Crying maiden sure melts a grown men’s heart huh

Uchida managed a small smile, the weight seeming a little lighter now.

“Make sure the crow is kept warm and undisturbed. If it shows any signs of worsening—like swelling, foul smell, or excessive lethargy, contact me immediately.”

He reached into his bag, handed a small note and his contact info for Hoshino sensei

Despite the old rain outside, hope gathering quietly alongside the dripping wet trees beyond the windows. As the vet advisor leaves the room, another knocks on the door.

“Sorry for the intrusion…”

—

The rain continues to downpour.

“Rika chan, What brings you here ?!” Uchida’s eyes flickered away, faintly reddened, but her tone remained steady.

“Minami chan… What happened ?! Are you okay ?”

“Uhhh… well…you know…our club pet was hurt ! I just… I guess I got a little emotional.”

Uchida glanced at us, as if silently asking us to understand beyond her words.

“Yea, the crow has been our club buddy for a while” I offered, a small lie to cushion her

“Oh no… Is everything alright ? It must be hard on you Minami chan…”

Kisaragi, ever practical, had already moved towards the kettle, the soft clatter of porcelain a familiar comfort. Uchida invited her friend to sit on the couch, the worn fabric offering a tangible sense of normalcy.

Someone knocked on the door again. I got up to open it.

“Sorry for the long wait, two special premium nigiri, one premium nigiri, ten sets of Gomoku Inari sushi, three servings of Wakadori karaage for Uchida sama”

“Thank you for coming all the way”

“Thank you very much for the patreonage!”

I glanced at the mountain of sushi in the bag, the vibrant colors put a smile on me

“Uchida… one-hundred fifty-five pieces of sushi? Are you skipping dinner tonight?”

Uchida gave a small laugh. “Well… let’s just say I have a healthy appetite when stressed. And don’t think you all are off the hook. I expect everyone to contribute and have a good time !”

Kisaragi’s eyes, usually so serene, held a determined anticipation as she turned from the kettle, a faint smile playing on her lips. “We’re counting on you, Uchida-san.”

Uchida grinned sheepishly. “Of course, of course. Someone has to lead by example.”

I carefully laid out the sushi boxes and utensils on the tea table, the faint, clean scent of sushi rice and the flavourful karaage. Kisaragi, with an artist’s precision, arranged the tea sets and poured for us, the delicate stream of sencha steaming gently into the cups. The soft, grassy aroma promised a quiet comfort, a moment of respite from the turbulent afternoon. Hoshino-sensei, meanwhile, was already happily munching on an Inari sushi, a tiny, almost imperceptible smudge of rice on her chin.

You fox, Hoshino-sensei, I thought, a surge of quiet affection for her sly, wise presence. You sly kitsune, just showed yourself.

“This is sencha, it would balance and pair well with the dishes.” Kisaragi murmured, her delicate long fingers tracing the rim of her cup.

“This sencha is from your family, Akari chan ? it smells wonderful” Uchida taking a delicate sip.

“I’m glad it suits your palate. Feel free to take some home,” Kisaragi smiled gently.

“This… this is nice. The club. The people…” Takami’s voice broke through

Our attention shifted toward her. “Sorry… I have said something weird…” She added

“Allow me to introduce myself—I’m Takami Rika, vice-president of the engineering club.”

“We’ve been collaborating with the University and government on a project to showcase at the Tokyo World Tech Expo next month.”

The food sat largely untouched, except for the one piece Hoshino-sensei stealthily grabbed before anyone noticed. Steam curled upward from our cups, carrying the soft aroma of fresh sencha.

“Let’s keep this casual, we can eat and talk” Takami offered a shaky laugh, breaking the tension.

“A-hahahaha…”

Uchida's forced laugh barely masked the tension, but it was enough to loosen our shoulders.

We raised our cups in quiet toast, the grassy bitterness refreshing my palate. Taking a piece of maguro, with just a hint of shoyu and wasabi, its delicate richness unfolded smoothly—the perfect savory comfort. The umami and subtle richness lingered beautifully. Kisaragi selected ikura, lightly covering her mouth as she savored her sushi, joy subtly shining in her eyes. Hoshino-sensei opted for hotate, Uchida started with Karaage.

“So, what exactly does this have to do with the math research club ?” I followed

“Right…You’ve probably heard about the unrest and strange phenomena in the building that have surfaced.”

“The experiments were fine initially, but mysterious tapping noises were heard and reported by bypassing students for the past weeks.”

“Cold spots linger nearby, lights flicker unpredictably and distorted whispers are heard in the hallway… The equipment readings were jumping erratically, instruments periodically report errors or calibration fail mysteriously”

“Our advisor tried to switch laboratories and buildings, re-calibrate the equipment… But in the end, it came to the same result…”

“And you know… In the club, things are not going well…and falling apart” She said it with a frown and disappointment

Kisaragi trembled and her palm curled up instinctively upon hearing those words

Uchida tries to comfort Takami, a quiet offer of support. We tried to eat, yet the sushi remained untouched.

“I suppose you are not here to spread more rumors right ? What is the project exactly ?”

“Yes… I have heard about Kisaragi san and the math club abilities, and I would like to ask for help in investigating the events and rumors.”

She bowed deeply. “The project is a quantum-grade microclimate chamber, designed to maintain stability for quantum photonics experiments. Please…”

Hoshino sensei choked on the tea. I gently petted her shoulder back while Kisaragi offered napkins.

A soft, almost imperceptible rustle came from the cardboard box where the crow rested, followed by a faint, low croon. The fragile sound seemed to carry a quiet warning. Outside, rain drummed steadily against the windows.

—

As the water boiled, Kisaragi refilled our cups with practiced elegance. We all watched her, anticipation quietly mounting — as the math research club president, her opinion mattered the most. Lost in thought, she seemed far away, brewing the perfect cup of tea as if measuring solutions beyond the teapot.

“What do you think president…”

Kisaragi blinked, returning to awareness.“Oh… I’m deeply sorry…I’m not sure how much help I can be for your project… but… I’ll try...”

“Hold up, are you sure Kisaragi ? We don’t even know the details yet…”

“Takami, I’m sorry to hear about this trouble you have with the project. But surely, you sought help from your advisors or supervisors first? Did they offer more than just moving labs?”

Takami shook her head.

“Some university students treat the collaboration as a mere resume booster, doing just enough to claim credit without addressing core problems. Others dismiss us as ‘just high schoolers,’ ignoring our feedback entirely. The faculty are overwhelmed and stretched thin, there isn’t much support beyond handing it back to us”

“Rika chan, How’s everyone holding up under all this pressure?” Uchida was concerned, holding Takami’s hand.

“To be honest, the atmosphere is tense. Some members have started blaming each other, and motivation has dropped severely. The rumors swirling around the building about spirits aren’t helping either, some have quitted”

Kisaragi’s hands trembled just enough to betray her mounting discomfort. Hoshino sensei reached out, gently holding her hand and exchanging a small, knowing smile.

Takami continued quietly, “Because of the project’s nature, there’s insufficient precedent or reference material for the strange anomalies we’re seeing. With morale so low and pride still high, we’re stuck. And the World Tech Expo presentation looms closer…”

She looked earnestly at Kisaragi. “I want to find the root of this. That’s why I need your help.”

This is a tough problem. It feels like a ship without a captain—no clear orders, and the senior members are caught up in their own struggles for control, often ignoring the insights of those below deck. Meanwhile, some crew are jumping ship altogether, and yet funding keeps pouring in, as if more resources alone could patch the leaks. We, the math club, have been brought aboard from another voyage, not only to pinpoint the root causes but also to take responsibility for repairing and steadying the course. We can no longer just observe the sinking ship — we have to help steer it back to safety or at least sinking at the right direction

“Why don’t we set some terms for negotiation, Takami ?”

“Of course, I’ll do my best to meet your expectation”

“First, this is a request given to the math research club, not Kisaragi alone. Regardless of the outcome of the investigation, responsibility lies within the club, not on Kisaragi alone”

“Second, I want your supervisor to acknowledge this collaboration officially, as I wouldn’t want to complicate the dynamics of our standings.”

“Third, all analysis and results belong to the math club, with publishing and presentation rights shared as appropriate”

“Fourth, the club requests appropriate funding to cover equipment, software, research and any travel essential for the project and Expo.”

“Fifth, we require full access to necessary data, labs, and personnel for effective work, plus timely updates from your side.”

Kisaragi’s eyes widened, her pupils dilating slightly. Hoshino sensei nodded continuously as a quiet support for my request, while munching on another piece of inari sushi.

Sensei stepped in, “I trust the math club’s academic commitments will be respected. Their participation must not compromise studies and goals. Also, the club reserves the right to withdraw if circumstances become untenable or conflict with its principles.”

“With these terms, the clubs can build a fair, respectful partnership that benefits all” Upon Hoshino sensei finishing talking, she gives me a wink. I returned a smirk.

You are really cute sensei

We all looked at Kisaragi again, checking for her approval. She returned a quiet smile and gentle nod, as she refilled our tea cup, with warmth.

“Fair deal, don’t you think? Takami ”

Takami paused thoughtfully, then extended her hand.

She smiled, slightly relieved. “This sounds fair. I’ll speak with my supervisor to formalize these points.”

Uchida chimed in, “I’ll prepare the documents for the arrangement then ! Please take it to your supervisor and seal it with your club crest.”

“One last request,” I pressed. “Please help us finish all this food..”

She burst into giggles,“Pffff, sure… of course! You are Kanzaki-san right ?” I nodded in response.

As we settled into the food, Uchida busied herself by printing the agreement on the club computer.

She leaned in, “You looked really cool just now… Hehehe.”

“Well, you know. To push a vessel well forward, all forces have to be balanced. Pressure decreases as surface area increases, right ?”

They all turned to me, their expressions shifting from surprise to delight. Kisaragi’s eyes widened slightly, a spark of amusement flickering within. Takami’s smile deepened, impressed. Uchida tilted her head, still trying to process my words. Even Hoshino-sensei grinned broadly, eyes twinkling.

“Kanzaki, where did you learn this pick-up line?” Hoshino sensei playfully spanked my back

“Ouch…It was revealed to me in a dream…”

Soft giggles filled the clubroom, warm and light like a familiar melody.

—

Finishing our meals, we cleaned the table while waiting for Takami to return with the signed document. In the end, we couldn’t finish everything, Uchida packed the leftovers to take home.

“Uchida-san, thank you for ordering and arranging this tea break for us. Please let the club cover the cost of the meal,”

“Akari-chan, really. It's no trouble at all. Don’t worry about it.”

“Please allow me. I wanted to make this a proper math research club welcome party for you and Kanzaki-kun. It’s been a long time since I enjoyed a meal like this…”

“Well then, if you insist… Thank you, Akari-chan, and thank you, Sensei!”

“Thanks for feeding us, the tea was superb. Kisaragi and Hoshino sensei”

“Not a big deal, as long as everyone’s full. You will all burn this energy off in no time” petting the crow softly.

Moments later, Takami returned and brought the sealed document. Hoshino-sensei carefully examined the terms and verified the signatures before adding her own. Uchida made a copy for Takami with quiet efficiency.

“Thank you Minami chan…shall we move to the engineering building now ?”

Kisaragi nodded, “Let's go then…” I said.

Hoshino sensei volunteered, “I’ll standby the math club then, in case there's any student coming. Kanzaki, call me if you need anything.”

“With the academy’s budget footing the bill, the engineering department gets access to university-level equipment, plus collaborative projects with industry and government labs.” Her eyes twinkled behind her glasses.

“it’s practically a gateway to the future”

She always sees ten steps ahead

I waved at Hoshino sensei, she returned a graceful wink

Takami looked at us curiously.

The sky dimmed under thickening rains, the fading light swallowed by approaching evening. As we neared the engineering building, the bustle of students thinned, replaced by the steady hum of high-efficiency air filters venting softly beneath sleek metal grates.

The building itself stood tall and modern, its glass facade reflecting the dimming sky like a beacon of innovation—a huge contrast from the older wooden classroom scattered across campus. Funding for this department alone had reportedly topped several billion yen over the past decade, a testament to Yugen Academy’s ambition to rival top universities and even national research institutes in cutting-edge technology.

“By the way, I need to leave by six tonight. My part-time job starts at seven, and it’s quite far.”

“Oh? Where do you work?” Uchida asked curiously

“Near Kyoto Shiyakusho-mae Station,”

“Hee, that’s indeed rather far from campus”

Kisaragi looked at me, “It’s still raining… If you don’t mind, I could perhaps give you a ride later, so you needn’t rush.”

“Really? That would be a lifesaver. Thanks, Kisaragi, I’m in your debt again.”

“Don’t mention it” She smiled

"It's quite a journey to Shiyakusho-mae. Do you all have long commutes to campus?” Takami asked

“I’m actually living in the dorms, so no commute for me,” I said.

“Okurayama ! my place is very close to Rika chan,”Uchida replied, Takami nodded in respond

“I live near Nanzenji,” said Kisaragi.

“Wow…As expected from the Kisaragi family. That’s pretty close to Kanzaki’s work, then,” Takami remarked thoughtfully.

“Guys…I have been wondering… Do you hear it ? A deep bass rumble…” Uchida asked

Kisaragi nodded in agreement, “Yea, I can feel it. It resembles a deep vibration more than a note”

Takami’s face paled, uncertainty flickering in her gaze.

“I… I don’t hear anything.”

I tried to focus, but all I could catch was the familiar drip of rain against the windows

“Do you two play musical instruments ? I am not hearing anything”

Takami shifted closer, her steps tentative as we moved carefully toward the engineering club, attuned to every possible sound, each illogical tremor whispering questions we were not yet ready to answer.

“Before, we go in… Please don’t take things they say personally. I’ll apologize beforehand” Takami gave us a deep bow.

At the heavy double doors, Takami paused to swipe her ID card against a biometric scanner. A low beep acknowledged her authorization, and the doors slid open silently. Adjacent to the doorway, a small airlock chamber awaited. We slipped inside, trading our regular shoes for sterile slipcovers and easing into lightweight lab coats hanging neatly on hooks. The chill of filtered, humidity-controlled air welcomed us—no hint of the damp spring rain outside—while soft white lights illuminated clean corridors lined with precise instrumentation.

“This area is a halfway clean room,” Takami murmured, fastening her coat pockets. “Not quite the full ISO six or seven class cleanroom, but enough to keep dust and EM interference harmless for most experiments.”

Passing a bank of glowing control panels, we glimpsed students—mostly a bit older than us, moving with quiet focus, some adjusting calibration knobs, others observing holographic readouts hovering midair. Despite the imposing equipment and strict protocols, the dedicated energy in the air felt almost electric—like the place itself was alive, humming with the promise of discovery.

We walked towards the lounge room. Takami and I entered first. Kisaragi and Uchida stayed behind us, the club room filled with unrest, energy and hostility.

“I have brought some skilled people to help with our project. They have already passed through the security check. Please be kind” Takami asserted

A heavy silence fell after Takami’s words. A group of students arguing at the back fell silent, their gaze turning suspicious and cold. Several engineering club members exchanged looks, whispers threading through the room like a restless wind. From the back, a tall figure stepped forward, arms crossed, eyes sharp and skeptical.

“Help, huh... And what exactly do you think you can help with?” His voice was low, measured, tinged with skepticism rather than outright challenge.

“Looks like we’ve got an overflow of advice now. As if we needed more distractions.”

Some voice from the back, “Isn’t that the scholarship welfare boy ? This project isn’t some math homework assignment.”

Takami lifted her chin with quiet resolve. “Our microclimate chamber is malfunctioning. Temperatures fluctuate wildly, pressures spike unpredictably — the whole system is unstable. We brought specialists to investigate and assist.”

A chorus of mutters rose. “Specialists, huh? And who exactly are these geniuses?” a student sneered.

I felt someone move behind me, Kisaragi emerged, her calm gaze sweeping the room. The air seemed to shift. Conversations stumbled, whispers faltered.

“That’s… Kisaragi Akari,” someone breathed near me.

“Wow…for real,” another whispered. “If she’s here, maybe there’s hope.”

Kisaragi met their eyes evenly,“We’re all here to solve the problem, and we’re not here to waste time or entertain skepticism. If you want to contribute, join the effort. If you want to obstruct, step aside. Progress demands cooperation, not suspicion or distractions.””

A quiet stillness spread through the room.

No one spoke immediately, yet the tension softened—like the light settling gently at dusk.

We looked at Kisaragi; her eyes met ours again, and for a brief moment, the firmness melted into a familiar, shy smile—a hidden warmth beneath the frost

Some lowered their gaze briefly; a few exchanged a glance weighted with thought.

The sharp edge of hostility dulled, replaced by a restrained respect mixed with lingering hesitation.

Well – hostility mainly towards me. Kanzaki Seiya took some damage

A person with glasses walked towards us, greeting Kisaragi, Uchida and me at last.

“Welcome ! To the engineering lab”

—

The laboratory was cleaner and more organized than I expected. The supervisor seemed absent.

“I’m Satou Shinichi, a third-year student at Tokyo University. I’m one of the project’s main designers, also an alumni of Yugen Academy. Thank you for coming all this way. I believe Takami-san has given you a brief overview already. It’s, well… a 1 cubic meter sealed chamber, designed to create a stable environment for quantum photonics experiments. We're still working on some parts, hoping to make it as precise as possible.”

“Well… Let's draw on the whiteboard…”

He sketched the chamber’s schematic, pointing as he spoke.

“Its main job is to create a stable, carefully controlled environment that keeps the experiment safe from outside disturbances—things like dust particles in the air, vibrations, sudden temperature changes, and electromagnetic noise. All of those can easily mess with the delicate quantum effects we’re trying to observe.”

“Quantum photonics plays a key role in three big areas, quantum computing, secure communication and industrial applications”

“As we estimate that as quantum computers become more capable, they could break RSA keys considered secure today within feasible timescales. I am sure the math research club members are very familiar with RSA ?”

We nodded together. Uchida leaned closer, almost breath brushing my ear. “Hey Kanazaki, what’s RSA again?”

Kisaragi shifted quietly, trying to catch what we were saying.

I whispered carefully, careful not to interrupt Satou-senpai, “It’s a cryptography algorithm that secures data transmission—you use it every day on your phone.”

Uchida’s eyes widened slightly as she whispered back, “Oh, the private key and public key thing!”

Kisaragi leaned in even more, voice soft and thoughtful, “RSA works because it’s easy to multiply two big prime numbers together, but very, very hard to do the reverse.”

Uchida nodded repeatedly, a small smile tugging at her lips. “Oh right.”

Kisaragi’s eyes softened briefly before she leaned back, letting the moment settle.

Their mingled scent lingering briefly before quietly fading away.

Outside our math geek little world, Satou-senpai continued.

“We use these nano-engineered thermoelectric fabrics combined with tiny microfluidic channels that carry special nanofluids. This lets us adjust the temperature really fast and precisely—down to just a few hundredths of a degree.”

“On top of that, ultrasonic humidifiers work together with smart sensors that ‘learn’ how to keep the humidity exactly right. That’s crucial for maintaining the coherence of the quantum dots.”

“Our ventilation system runs on AI with machine learning, so it can predict and actively counter any environmental disturbances in real time—kind of like having a watchdog that never sleeps.”

“And the chamber walls themselves? They’re coated with programmable metamaterials designed to block out electromagnetic and acoustic interference below certain frequencies, so almost no stray noise gets through to disturb the experiment.”

I asked, “Interesting, are you employing Peltier elements within the thermoelectric layers, or relying solely on convective cooling within the microfluidics?”

Satou blinked, a trace of surprise flickering and he looked at Takami, she returned an approving nod and smile.

Satou smiled and continued, “That's a good question. Primarily Peltier modules, augmented dynamically by fluid flow modulation within the microchannels, which reduces thermal lag. Are you familiar with MEMS-integrated microfluidic cooling?”

“Somewhat familiar, achieving both stable laminar flow and minimal acoustic vibrations within microchannels is tricky, especially at cryogenic ranges typical for quantum photonics.”

Kisaragi added softly, “Memristive sensors add adaptive feedback control, but have you considered the potential temperature drift over long timescales due to sensor hysteresis?... Continuous sensor recalibration might be necessary.”

Satou nodded, impressed. “We apply periodic sensor calibration algorithms synced with AI controls, but you’ve pinpointed a critical challenge.”

I continued, “Regarding the AI system— how do you collect training data? Simulations alone can’t fully capture unpredictable environmental fluctuations like intermittent EMI spikes.”

“We’ve implemented hybrid learning, initial training on simulated data, then reinforcement learning using real-time sensor input. The system adapts continuously, but it’s still a work in progress.”

The room fell still, the weight of their technical exchange sinking in. Even Takami looked at us with renewed respect. Several students whispered among themselves, eyes flicking between us.

Satou finally broke the silence. “Your grasp of the system’s nuances is impressive. I didn’t expect visitors, especially from the math research club, to dive so deeply.”

“I guess it’s more than just ‘math homework assignment’” I gazed back at the crowd of anti-circlist. Satou and Takami smiled wryly.

Kisaragi giggled gracefully covering her lips, “….complex problems require collaboration across disciplines, and mathematics is the native language of all science discipline”

Uchida slipped in, determined, “The math research club eats problems for breakfast !”

I gave her a wink and thumbs up. She blushed faintly, shy but proud.

Nice follow, Uchida—definitely applying a team-wide buff right when we needed it. That little magical cast of support energized us all.

Kanzaki Seiya has recovered to full health !

—

We had gained a clearer understanding of the project’s roadmap from our brief technical exchanges. Yet, despite its ambitious goals, the project revealed many loopholes and unresolved issues—breeding confusion and unrest within the club and across the school. Nothing was ever quite as straightforward as it seemed.

Takami distributed the research analyses and documents to us. A thick stack of papers lay on the lounge desk. We settled down as if entering a corporate meeting room. I found myself sitting closely between Kisaragi and Uchida—their familiar fragrances slowly pulling my focus away.

Kisaragi immediately dived into the papers, her delicate fingers resting thoughtfully on her chin. The usual Kisaragi had returned—elegant, composed, and lethal in her reasoning. I caught myself lingering on her calm face longer than intended. The quiet in the room thickened.

Takami added. “As mentioned before and the documents presented, temperatures plunge suddenly from normal 298 K to 278 K, nearly -15°C—then spike instantaneously to 313 K, all within a matter of seconds. The AI struggles to compensate, faltering and misaligning the sensitive laser optics that keep quantum coherence steady.”

Her gaze drifted to the others, heavy with exhaustion. “Pressure swings of ±2 kilopascals occur rapidly, altering the microclimate density inside the chamber, threatening the trapped photons’ stability in the quantum dot arrays.”

The precision needed for quantum experiments was razor-thin, any disruption spelled catastrophe.

She continued, “Meanwhile, disturbing phenomena feed unrest in the building: rhythmic tapping echoes through the ventilation ducts like a ghostly metronome; inexplicable cold spots lurk near labs; lights flicker unpredictably from unknown electromagnetic interference, and distorted whispers float down hallways, fueling rumors of spirits tied to the rising academic tension.”

Uchida shivered, swallowing hard. Holding the documents while looking slightly nervous.

“We tried troubleshooting, focused on hardware, but lacked the analytical depth. Teachers are stretched thin—overwhelmed and busy…”

The room grew charged with quiet tension as the engineers exchanged glances, their frustration slowly surfacing beneath measured words.

One young engineer club student shifted uneasily and finally spoke, voice low but firm.

“Perhaps the sensors aren’t the root problem. If mechanical resonance is present in the system, then filtering through AI won’t be enough. We need to focus on physically decoupling these vibrations.”

Another chimed in, careful yet resolute.

“I agree. Our vibration isolation isn’t flawless. The ducts carry micro-pressure changes, and when heavy equipment nearby operates, it likely worsens these effects.”

Satou’s eyes narrowed slightly, his tone calm but pointed. “If that’s so, then why do the malfunctions appear so chaotic and unpredictable? Physical resonance tends to be consistent.”

Takami gave a thoughtful nod. “Intermittent mechanical coupling could explain sudden spikes, but the cold spots and flickering lights? Those don’t seem to fit any mechanical pattern.”

Uchida’s voice sharpened gently, tinged with frustration. “Could the metamaterial shielding coatings have developed microfractures, compromising electromagnetic isolation?”

A technician responded carefully, balancing deference and conviction. “The shielding design specifications surpass typical environmental noise. If flickering and cold spots are genuine, we may be facing software errors or faulty sensor readings instead.”

Kisaragi leaned in, quiet but authoritative. “Random sensor noise causes chaotic, uncorrelated data. But here, anomalies correlate closely with environmental variables—temperature and pressure. This points toward nonlinear dynamic interference, not mere instrument failure.”

Satou exhaled, tension visible in his posture.

“Right, nonlinear dynamics escape straightforward modeling. Our AI struggles with unpredictable forcing inputs…”

Kisaragi continued, “The chamber’s behavior reflects a nonlinear system governed by differential equations like the Duffing equation. Such systems can exhibit chaotic attractors, where even tiny perturbations lead to vastly different outcomes.”

She pointed at the phase portrait on the documents.

“See this strange attractor? It means despite deterministic equations, long-term prediction is nearly impossible. The AI struggles because it tries to fit linear corrections to inherently nonlinear disturbances.”

They all agreed “Right, spot on Kisaragi...”

So to speak, If you push gently and regularly, the swing goes back and forth in a smooth, predictable way. You know exactly where it will be after a few pushes.

But sometimes, if you push with different strengths or at different times, the swing can start moving in a very strange way, jumping around unexpectedly. It might even go in directions you didn’t expect and not stay steady.

This is kind of like what is happening inside the experiment chamber. The machines and computers try to keep things steady and calm, like making sure the swing moves smoothly. But because many things — like temperature and pressure — keep changing in weird ways, the system starts acting “chaotic.” That means it can be very hard to predict what will happen next, just like the swinging gets wild and unpredictable.

Satou-senpai suggested. “Kisaragi-san, and math research club fellows. Thank you very much for the input so far. Why don’t we take a short break, organize and digest all the information first ?”

“That would be helpful, Satou senpai. Thank you”. I said and he nodded.

The hum of the lab’s air filters filled the silence as we gathered in a quiet corner, away from the chamber’s sleek silhouette. I took a deep breath, feeling the weight of the challenge ahead.

“Alright, math fellows, we need to figure out what’s causing these malfunctions independently. Let’s start by reviewing the chamber’s logs and data for any patterns or anomalies.”

Kisaragi’s eyes flicked toward a nearby computer terminal. “I’ll handle the data analysis, I’m familiar with their logging software” she said softly, her calm demeanor belying her razor-sharp focus.

Uchida bounced on her heels, eager to jump in. “I’ll help! I’m great at spotting trends in big datasets.”

“Perfect, meanwhile, we should inspect the chamber itself. There might be a hardware issue we can pinpoint.”

Satou stepped in, adjusting his glasses. “I can guide you through the chamber’s components and explain anything you need.”

I nodded. “That’d be a huge help. And we should also talk to the engineering club members later, see if they’ve noticed anything odd that might give us a lead.”

Takami, standing nearby, crossed her arms with a determined look. “I’ll round up the team and set up interviews. We’ll get you whatever info they’ve got.”

“Great, let's reconvene here in an hour with what we find. And keep an open mind—there’s more to this than meets the eye.”

With a shared nod, we split up, each of us fueled by a mix of curiosity and resolve.

I glanced at Kisaragi—her serene expression softened with resolve as she headed to the terminal.

Uchida’s energized steps echoed softly down the corridor, while Takami looked at me curiously and gave me a smile.

I inhaled deeply, feeling the weight of the path ahead.

Rain pattered on the windowpane like a secret rhythm—one we had yet to understand.

Kisaragi glanced at the clock, then met my eyes. A brief exchange of raised eyebrows passed between us, a silent reminder to keep track of time.

In that flicker, something calm yet unspoken hung in the air, like a quiet invitation that neither of us was quite ready to acknowledge.