Chapter Text
Izuku didn't wait for breakfast.
The sun was a mere suggestion behind the winter clouds when he reached the massive, heavy doors of the Principal’s office at 7:00 AM sharp. He felt like he was vibrating out of his skin, his pulse a frantic staccato in his throat. Beside him, Oboro was doing literal laps around the hallway ceiling, his blue-white form trailing ribbons of static as he tried to burn off the nervous energy that came with being a dead man about to make a formal introduction.
"Come in, Midoriya-kun!" Nedzu’s cheerful, high-pitched voice rang out before Izuku’s knuckles could even graze the wood.
“How’d he know it was you?” Oboro gasped, “Can he see through walls?”
“I emailed him.”
The doors swung open with a mechanical smoothness. Nedzu was perched behind his desk, a steaming cup of tea held delicately in his paws. His beady black eyes were twinkling with an intensity that suggested he had been expecting this visit since the moment the first encrypted file had floated in the archives. Or maybe since the moment Oboro had accidentally short-circuited his GPS during their first outing. Oops.
"I must say," Nedzu chirped, gesturing with a paw to the chair in front of him. "I’ve been quite curious what business you might have today. Is it about One For All? I don’t suppose it’d be having ramifications on your health?"
“Again with the One For All!” Oboro remarked, dropping from the ceiling to hover cross-legged in the air. “Seriously, Izuku, you’ve gotta tell me what the deal is with that. Even the rat is in on it!”
Nedzu’s gaze shifted ever so slightly. “And is it wrong to assume you've brought your... invisible companion with you?"
Oboro stopped mid-flight, his form flickering. "Can he see me? Wait, he just said inevitable, which implies he can’t… So is he just that good at guessing?"
Izuku didn't move for a heartbeat, his pulse thrumming in his ears. He looked from the small, impeccably dressed principal to the floating ghost. The silver cloud studs in his ears felt like they were burning. Or maybe that's just his actual ears.
"I... I can't speak for what you see, sir," Izuku started, his voice steadying as he sat down. "But yes. He’s here. And he’s the reason I—we went through your old files.”
Nedzu took a slow, deliberate sip of tea, his eyes never leaving the empty space where Oboro was currently hovering in a state of shock, while the chimera himself did not seem the least bit surprised. "I don't 'see' him with my eyes, Midoriya-kun. I am a creature of logic and observation. I see the displacement of air, the localized drop in temperature, and the way your pupils track a specific point in space that should be empty. Plus," the principal tilted his head, a predatory gleam in his eye, "The way my digital clock has been running backwards since you entered the room is a bit of a giveaway."
"He's good," Oboro whispered, drifting down until his feet were inches from the floor. "He’s really good.” He glanced up at the clock himself and his eyes widened, “Uh— woah, uh, tell the rat I’m sorry about the clock. I guess time is... weird."
"He says he's sorry about the clock," Izuku translated, he didn’t know Oboro could do that, or maybe this was a new ability? He reached into his bag, pulling out the folder of notes on Oboro’s memories, the accident details, and photos of the construction site he snapped before they left. "And to answer your first question, sir... this isn't about One For All. Uh– well, not directly at least. This is about a student who never got to go home."
“You make me sound so tragic, Izuku,” Oboro muttered, but the green-haired teen didn’t feel inclined to laugh.
Nedzu’s cheerful demeanor didn't vanish, but it sharpened. He set his teacup down with a soft clink that made a pleasant sound against the wooden desk. "A student? You speak in the singular, yet the weight of your tone suggests something much older than a current classmate."
"Thirteen years older, to be exact," Izuku said, sliding the folder across the desk. "Principal Nedzu, this is Shirakumo Oboro. The records say he died in a work study from falling debris. They– they say he died on impact... but… but the file is wrong. So, so wrong."
The silence that followed was absolute. Nedzu’s paws hovered over the folder. He opened it, his eyes scanning Izuku’s frantic handwriting and the blurred photos of the construction site.
"Tell him about the alleyway," Oboro urged, his form flickering with a spike of anxiety. "Tell him before Shouta calls my parents and they think you're a loon for bringing them a fake letter."
"He’s worried about his family, sir," Izuku added quickly. "I visited them yesterday. I gave them a letter he dictated to me—And I– I know, I know I shouldn't have gone without permission, but I couldn't leave them in the dark. But now Aizawa-sensei is suspicious. He smelled the incense they use. He saw the tea cakes, which, uh—you probably have no clue what that means… nevermind, sir, if he calls the Shirakumo family before we explain this... he won't be able to handle it."
Nedzu turned a page, his gaze landing on the sketches Izuku had done of Oboro “A letter from the dead," he murmured. "A very bold, very human mistake, Midoriya-kun."
"I don't think it was a mistake, sir," Izuku whispered, his resolve hardening. "The Commission put this case on hold. They probably thought there was no point in it. But let me reopen it. Please."
Nedzu looked up, his expression unreadable. "You realize that if what you're suggesting is true—that Shirakumo-kun’s physical form is still functioning… while his… soul, for lack of a better word, remains here—that could mean someone is using his body for ill-intent, and then we are looking at a tragedy of unprecedented proportions. But I must ask; why come to me instead of your homeroom teacher?"
"Because Aizawa-sensei is too close to this whole… situation," Izuku said firmly, that was it. The only reason. "He wouldn't be an investigator; he'd be a victim and he was directly involved in the inciting incident. I—I need you to be the logic, Nedzu-sensei. I need you to call the family and protect them before the truth reaches them in the wrong way."
“Woah, way to assert yourself, kid.” Oboro huffed.
Nedzu stared at the empty air. "Shirakumo-kun," he said, his voice surprisingly soft. "If you can hear me... could you move the teacup to the left? Just so we can establish a baseline for your physical influence on our reality?"
Izuku wasn’t sure the principal needed a “baseline,” instead, maybe he needed just one more show of proof to commit himself to the two boys. So when Oboro looked at Izuku, then at the cup, Izuku nodded, a silent, go for it. Oboro focused, his brow furrowing as the air around the desk began to hum with blue static. Slowly, with a grating sound, the fine china slid three inches to the left.
Nedzu’s beady black eyes blinked. He picked up his desk phone. "I see. Midoriya-kun, stay here. I’m going to make a few calls. First, to the Yokohama police to ensure the Shirakumo residence is taken care of. Second..." he paused, his paw hovering over the keypad. “I suppose you'd like to keep both Aizawa and Yamada out of this for now?”
“Yes, please.” Izuku said quietly.
"Excellent," Nedzu said, flicking his tail. "Now, Midoriya-kun, there is the matter of your punishment. You have engaged in unauthorized investigative work, accessed classified archives under false pretenses, and left campus for an unauthorized errand."
Izuku winced. "I'm sorry, sir."
"You will be," Nedzu said, nodding. "Your punishment is as follows: You will spend your winter break here assisting me in the decryption of these files. You will not tell your classmates, and you will maintain the facade of 'remedial studies.' If your homeroom teacher asks, you are under my personal supervision for... let's call it training. But you will be permitted to leave campus under my permission."
"Wait," Izuku blinked. "That's it? That sounds like what I was going to do anyway."
"Is it really? But Midoriya-kun," Nedzu giggled, a sound that made Oboro-–a ghost—shiver. "You clearly haven't seen the sheer volume of paperwork I intend to make you file. It will be grueling.” Then Nedzu’s expression then softened and his smile became less conniving. "Go back to your dorms. Eat breakfast. Act normal. I will handle Yokohama. But Midoriya-kun?"
Izuku paused at the door. "Yes, sir?"
"The One For All is already quite a heavy burden," the principal said, looking back at his tea. "But secrets involving the dead have a way of becoming even heavier. So, please, be careful."
Izuku nodded, “I will.” As the doors closed, Oboro let out a shaky breath. "He's definitely scarier than any villain, Izuku. But... at least, he’s gonna help."
Izuku gripped his backpack straps. "He's right, though.”
"Damn that rat."
"Please stop calling him a rat," Izuku hissed under his breath as they hurried down the hallway, the heavy silence of the administration wing making every footstep sound like a gunshot.
"Fine. The highly-intelligent-possibly-god-complex-having-rodent-thing," Oboro amended, though his flickering form still looked a bit frayed at the edges. "But Izuku, he knew. He knew about the 'One For All' thing. How many people know your life story? Is there a newsletter? Where can I subscribe?"
Back in his own office, Aizawa Shouta stared at his phone, his thumb hovering over the screen. He had been five seconds away from calling a contact in the Shizuoka police department to verify a hunch—a hunch he told himself was illogical, paranoid, and fueled by a lack of sleep.
Then, the notification chirped.
FROM: Principal Nedzu
Shouta, I have decided to pull Midoriya Izuku into a series of intensive remedial studies and Quirk theory workshops under my personal supervision. He will be occupied for the remainder of the semester and through the winter break. Please adjust your records accordingly. No need to fret over his whereabouts; he is in capable paws!
To put it in a simple way:
What the fuck?
Shouta exhaled a sharp, jagged groan as he tossed his phone onto the desk; the device landed with a dull, dismissive thud against the wood. He dragged his hands over his face, the rough grit of his stubble scraping audibly against his palms.
The logic didn't track. Midoriya was undeniably a problem child, but his academics remained solid and his mastery over his Quirk was steadily gaining ground. There was no rational basis for Nedzu to abruptly sequester the boy for "remedial studies"—especially not moments after Midoriya had returned, leaving the faint scent of a memory and balancing a bundle of tea cakes that Shouta remembered a mother gifting to him during his adolescence.
"It’s a coincidence," Shouta muttered to himself, his voice sounding hollow against the silence of the empty office.
The math was impossible. Midoriya was barely sixteen; he would have been a mere toddler when the disaster struck. The name Shirakumo Oboro should have meant nothing to him unless he had spent weeks submerged in the dust of redacted cold cases. And yet...
He stood, his chair scraping the floor as he moved toward the window. Down below, the small figure of Midoriya was visible, jogging toward the 1-A dorms with his chin tucked low against his chest.
Shouta’s gaze sharpened, his eyes narrowing into slits. Nedzu was meticulously guarding a secret, and Midoriya was somehow connected into the center of it.
"I don't believe in coincidences, Nedzu," Shouta whispered, his fingers curling tightly into the familiar, weathered fabric of his capture scarf.
English class was exceedingly slow, an agonizing contrast to the frantic pace of the last forty-eight hours. Despite Mic-sensei’s boisterous laughter and high-strung energy, the air in the room felt stifling, thick with the unsaid.
Izuku sniffled, the sound sharp and jarring in a brief moment of quiet as Present Mic clicked a remote to change a slide on the board.
Kacchan shifted in his seat, his chair creaking as he turned around. His eyes were narrowed into a warning glare, sparks practically simmering behind his pupils. “You better not get me sick, nerd. I’m not getting stuck in the dorms for a week because you’re a walking ice box.”
“Uh—sorry,” Izuku muttered, his voice coming out smaller than intended. He pulled his shirt collar up a bit higher, trying to hide the silver studs that felt like they were humming against his skin.
Oboro, who had been lazily floating through the ceiling fans to see how fast he could go without losing his "cloud-form" cohesion, drifted down. He leaned in so close to Izuku’s face that their noses would have touched if the ghost had been solid. He tilted his head, his blue eyes searching. “You’re sick? You don’t really look it, ace. No runny nose, no flushed cheeks. You’re just... pale.”
Izuku touched a palm to his cheek; his skin felt cool, almost unnaturally so. He wasn't feverish. If anything, he felt like he was slowly being packed in dry ice. There was a strange, heavy ache deep in his chest—a sensation of thousands of tiny pins and needles beginning to prick his insides from the center out. Now that he thought about it, the feeling had been creeping up on him for the past few days. Ever since that night in the dorms, he had felt just a little bit colder every hour.
“You okay?” Oboro asked, his playful energy vanishing as he noticed Izuku’s slight tremor, the ghost placed his hand on Izuku’s arm. “You do look a little—bleagh, but I just thought that was just your face.”
Izuku’s heart hammered against his ribs, but the beat felt sluggish. He couldn't answer out loud, not with Kacchan watching him like a hawk and Present Mic standing just ten feet away. He gripped his pen until his knuckles turned white and scribbled a tiny, jagged note in the margin of his English notebook:
I'm fine. Just tired. The room is just cold.
"Midoriya!" Present Mic shouted, pointing a finger at him with a theatrical, wide-mouthed grin. "You look like you're in another dimension, listener! Care to translate this sentence for the class? Put some SOUL into it!"
Izuku jumped, his chair scraping loudly against the floor. "Y-yes, sir! Sorry!"
As he stumbled through the English translation, his tongue felt heavy, like it was made of lead. Mid-sentence, he caught a movement in the hallway. Aizawa was passing by the open classroom door on his way to the faculty lounge. The man didn't stop, but he slowed down for a fraction of a second. His dark eyes didn't land on the board; they landed directly on Izuku, then shifted to one side of the boy. Then to the other where Oboro was hovering. The ghost sucked in a breath and squeezed—yes, because his translucent form found a way to make it feel like he was solid— as hard as he could on Izuku’s arm. The green haired boy winced, his own hand flying to the spot where the ghost had grabbed.
Aizawa’s expression didn't change, but his hand drifted toward the capture scarf around his neck—a subconscious habit he had whenever he sensed a threat, even one he couldn't quite see.
Oboro immediately pulled back, his blue eyes following his best friend. "Sorru, Izuku. He’s looking for me," he whispered, the mist around his shoulders thickening. "He can't see me, but he’s looking. Ace, your 'remedial studies' with the rat better start soon, or Shouta’s going to corner you in the hall and force the truth out of you."
Izuku sank back into his seat as Mic moved on to the next student. He looked down at his hands; they were trembling. He realized with a jolt of terror that the "pins and needles" feeling wasn't just in his chest or arm anymore. It felt like it was creeping up his throat.
Yamada Hizashi—known to most of the world as the high-decibel hero Present Mic—was a master of reading a crowd. Whether it was a stadium of ten thousand fans or a classroom of twenty teenagers, he lived for the "vibe."
And right now, the vibe in 1-A was freakin' weird.
From the front of the room, Hizashi kept his grin wide and his energy dialed up to eleven, but his internal radar was pinging. Usually, Midoriya was a font of frantic energy—muttering, scribbling, and radiating a warmth that almost matched his usual enthusiasm. Today, the kid looked like he was fading into the background of a black-and-white movie.
Hizashi clicked the remote to the next slide, his eyes darting toward the green-haired boy. Midoriya had his collar pulled up so high it nearly touched his ears, and he looked... brittle. Every few minutes, the kid would sniffle, a small, sharp sound that seemed to set Bakugo off.
“You better not get me sick, nerd,” Bakugo snarled.
Hizashi saw Midoriya flinch. The boy touched his own cheek, and for a second, Hizashi saw a flicker of genuine confusion on the student's face.
Something’s wrong, Hizashi thought, his mental "DJ" persona momentarily giving way to the concerned teacher.
He decided to test the waters. "Midoriya!" he shouted, throwing out a theatrical finger-point. "You look like you're in another dimension, listener! Care to translate this sentence for the class? Put some SOUL into it!"
Midoriya practically levitated out of his chair, the screech of metal on the floor making Hizashi wince. The boy’s translation was correct, but his voice... it lacked the usual spark. It sounded thin. Distant and hollow, even. And he was clutching onto his own sleeve like he was trying to warm the particular spot up.
Out of the corner of his eye, Hizashi saw Shouta move past the doorway. His husband’s pace faltered for a heartbeat—a micro-expression of intense focus that most people would miss. Shouta wasn't looking at the board. He was looking at the empty air around Midoriya, his jaw tight.
Shouta worried about something, Hizashi realized, his heart sinking. And if he’s worried, I should be terrified.
The bell rang, and the classroom exploded into its usual chaotic energy as students scrambled toward the door. Izuku was slow to pack up. His joints felt stiff, as if the marrow in his bones had been replaced by slush, and his fingers fumbled clumsily with the edges of his notebooks.
"Hey, hey, hey! Hold up a sec, Midoriya!" Hizashi called out, keeping his tone light and breezy as he wove through the desks.
Midoriya looked up, and Hizashi felt a sharp jolt of alarm. The boy’s eyes were glassy, and his skin had a translucent, marble-like quality. He was still holding his arm, Even the freckles on his cheeks looked faded, like old ink washed thin by water.
"You're looking a little rundown today, listener," Hizashi said, stepping into the boy’s space. He leaned down, searching for that usual spark of his usual energy. "Everything okay? You're not coming down with something, are you?"
"I-I'm fine, Mic-sensei," Midoriya stammered, his breath hitching in a way that sounded like glass rattling in a box. "Just stayed up a bit too late studying. You know how it is. Notes... hero data... it gets ahead of me."
"I do, I do! But the brain needs its rest to keep the rhythm going!" Hizashi laughed, his boisterous persona acting as a shield for his growing concern. He reached out, intending to give the kid a reassuring, gentle hand on the shoulder.
The moment his palm made contact with the fabric of Midoriya’s uniform, the smile died on Hizashi’s face.
It wasn't just that the boy was "chilled." Midoriya was freezing. To say it felt like reaching into a deep freezer in the middle of a mountain blizzard, wouldn't be enough. The cold didn't just sit on the surface; it vibrated, an unnatural, biting frost that seemed to radiate from within the boy’s chest, piercing through layers of clothing to sting Hizashi’s skin.
Hizashi didn't pull his hand away, though his fingers twitched with the instinctive urge to flee the cold. He tightened his grip, a futile attempt to share some of his own warmth.
"Midoriya," Hizashi’s voice dropped, the "Present Mic" persona slipping away to reveal the worried teacher beneath. "You're like ice. Are you okay, kiddo? We should get you to Recovery Girl.”
"No!" Midoriya gasped. The word came out as a puff of faint white mist.
What the hell?
Midoriya noticed, and clamped his scarred hand so violently and so quickly Hizashi was afraid he’d hurt himself. The kid stepped back so abruptly that Hizashi’s hand fell to his side, dead and numb. He took the hand away from his face. "I'm okay! Really! I think... I think the AC is just blowing right on my seat today. I'm going to go get some hot tea. So, I'll be fine, I promise! Sorry to worry you!"
Before Hizashi could protest or reach for him again, Izuku was out the door, moving with a frantic, desperate speed that didn't match how sluggish he’d looked moments ago. And although Hizashi could not hear or see the ghost, Oboro trailed behind Midoriya, looking back at Hizashi with a face full of guilt. "Izuku, he’s shaking. You’re literally turning into a popsicle.”
Hizashi stood in the empty classroom, staring down at his own palm. It was pale, the blood drained from the tips of his fingers. The air where Izuku had been standing felt heavy and thick, smelling faintly of ozone and a hauntingly familiar floral scent—like rain-drenched hydrangeas on a summer afternoon.
"Shouta," Hizashi whispered to the silence, his voice trembling as he felt the ghost of a memory chill his very soul. "What the hell is going on with that kid?"
Down the hall, hidden from view, Izuku pulled up his sleeve. There, on the skin where Oboro had been clutching him, a thin, crystalline patch of ice was beginning to form.
Nedzu’s office was a sanctuary of dimly lit precision. The only illumination came from the cool, clinical glow of three high-definition monitors and the soft, rhythmic hum of a server rack tucked discreetly into the corner. Despite the crushing gravity of the ordeal—and the fact that Izuku Midoriya looked like he was vibrating on a frequency of pure, unadulterated anxiety—Nedzu offered a delicate porcelain cup of tea. Izuku didn't take it. His hands were too busy clenching his knees as he stared at the digital files projected on the wall. Each file was a ghost in its own right—a piece of a life that had been systematically and ruthlessly erased.
"The Hero Public Safety Commission is a complex entity, Midoriya-kun," Nedzu began. His paws danced across a holographic keyboard with frightening, fluid speed. "When they 'halt' an investigation, it usually suggests one of two things: either they have reached a dead end, or they have found something that threatens the status quo. In Shirakumo-kun’s case, it appears to be a calculated combination of both, complicated by a severe lack of physical evidence at the scene of the collapse."
Nedzu pulled up a wireframe blueprint of a gray, nondescript building on the outskirts of Musutafu. "My internal audit of the Commission's financial records and personnel logs shows no direct involvement in the 'harvesting' of students. They are not the ones who took him. However," he tapped a red folder labeled [K.G.B.], "they are guilty of gross negligence. They classified this acronym thirteen years ago as 'Low Priority,' and then—most curiously—sealed it under a Tier-1 encryption."
Oboro leaned over the desk, his blue eyes scanning the data. The light of the monitors passed right through his chest, casting a faint, ghostly cyan shadow on the floor. "K.G.B.," he muttered, his brow furrowing in deep confusion. “I still don’t know why that would be in my file. I was a seventeen-year-old kid with a cloud Quirk and a C-average in math. I wasn't anybody important."
"He says he doesn't understand why he'd be linked to that," Izuku translated, his voice sounding hollow and metallic. "He was just a student."
Nedzu swiveled his chair, his black, bead-like eyes fixing on the exact space where Oboro was hovering. The Principal’s intelligence was so vast, so encompassing, it almost seemed like he was looking directly into Oboro’s soul, despite the lack of physical sight.
"Shirakumo-kun," Nedzu said, his voice dropping an octave into a serious, resonant tone. "Memory is often tied to the physical brain, but as you are currently demonstrating, the 'self' can persist beyond biological constraints. Can you remember anything about the gap? The moments between the rubble falling and... waking up into this form? Can you remember anything about where you were held?"
Oboro went very still. He closed his eyes, his form flickering like a television losing its signal in a storm. The temperature in the room dropped a sudden, sharp five degrees.
"Darkness," Oboro whispered. His voice sounded thin, as if it were coming from the bottom of a very deep well. "Cold. I remember smells... like chemicals and old flowers. And a voice. Someone was always talking to me, but it wasn't with words. It was like they were channeling static into my head."
Izuku relayed the words, his own breath hitching as he felt a wave of Oboro’s sudden, visceral fear wash over him like a tide.
Nedzu tapped his chin thoughtfully. "A voice that remind you of static. Fascinating. And the acronym? K.G.B.? Does it spark any visual? A logo? A sign on a door?"
Oboro shook his head slowly, his blue hair drifting like heavy mist. "No. I... I can't reach it. It’s like there’s a wall in my head. I can pass through actual walls now, but that one? It’s solid."
Izuku repeated the sentiment, his voice trembling slightly as he tried to create fiction on his arms.
"It seems," Nedzu mused, his eyes narrowing, "that while our friend can influence the physical world through sheer force of will, his own past is being guarded by a very specific kind of mental trauma—or perhaps, a Quirk-induced block."
Nedzu looked at Izuku, his expression shifting, becoming less like a teacher and more like a high-level tactician. "We have the who, Midoriya-kun. Now we need the where. And I suspect the answer lies in why you are currently the temperature of a corpse."
“Huh?” Oboro and Izuku said simultaneously, their voices echoing in the quiet office.
Nedzu set his teacup down with a precise, clinical click that seemed to punctuate the gravity of the moment. He leaned forward, his dark, unreadable eyes tracking the way Izuku’s breath puffed into a faint white mist in the center of the heated room. It was a phantom vapor, so delicate Izuku could barely see it, but to Nedzu, it was a glaring biological red flag.
"Midoriya-kun," Nedzu said, his voice shedding its playful lilt for something far more analytical. "You aren't sick in the biological sense. You are experiencing thermal siphoning."
Oboro drifted closer to Izuku, his expression shifting from confusion to a sharp, jagged guilt. "Thermal... what? Is that a science thing? Am I doing that to him?"
"He’s asking if it’s him," Izuku whispered. His teeth chattered as a fresh wave of cold washed over his shoulders, settling deep into his marrow.
"Inevitably," Nedzu replied, tapping a rhythmic cadence on his desk. "Based on your descriptions, Shirakumo-kun is a 'tethered entity.' He lacks a physical engine to generate the energy required to remain visible or interact with our world. Since he is currently 'anchored' to you—possibly through your shared emotional connection—he is using your body as a battery."
Nedzu gestured toward the monitor, pulling up a complex diagram of an energy transfer system.
"To maintain his form and move physical objects, he requires energy," Nedzu continued. "Since he cannot eat or breathe, he draws caloric heat from his host. You are quite literally burning your own body temperature to keep him from fading into the ether. The more he interacts—by doing more than moving small objects or speaking—the colder you will become."
Oboro recoiled as if he had been struck, his form flickering like a dying candle. "Izuku... I’m freezing you? I’m killing you just by standing here?"
"No," Izuku said firmly. He looked directly into the empty air where he knew Oboro was, even as his vision began to blur slightly at the edges. "No, we just have to be more careful. It's just... a trade-off. Right, Principal?"
"For now," Nedzu warned, his whiskers twitching. "But if your core temperature drops below a certain threshold, your heart will begin to struggle. We must find a way to stabilize his presence, or better yet, find where his original physical 'engine' is being kept."
Nedzu’s gaze returned to the K.G.B. file. "If we find the source of the project, we may find the energy source they used to keep his physical body’s 'vessel' functioning. But you, Midoriya-kun, are currently his spirit’s vessel. And a human body makes for a very inefficient radiator."
Nedzu tapped a key, and a new window opened on the center monitor, displaying a live thermal readout of the room. Nedzu appeared as a bright, pulsing white-orange. Izuku, however, looked like a fading ember. His core was a dull, sickly yellow, while his extremities—his hands and feet—were a deep, bruised purple, indicating a rapid and dangerous loss of heat.
"Look at the gradient, Midoriya-kun," Nedzu noted, pointing a sharp paw at the thermal monitor. Izuku waved his arm and on the screen, it was reflected as a jagged silhouette of deep blue against the fading orange of his torso. The ice crystals on his sleeve looked like little snowflakes.
“In classical thermodynamics, the Law of Entropy suggests heat flows from a higher temperature to a lower one until thermal equilibrium is reached," Nedzu explained. "But you are not reaching equilibrium because the 'threshold'—Shirakumo-kun—is a bottomless pit. He is essentially an endothermic reaction taking place in real-time. He is consuming your thermal energy to overcome the entropy of being a disembodied consciousness."
Nedzu tapped a key, and the fundamental heat formula appeared on the screen:
Q=mcΔT
"He is the Q in this equation, Midoriya-kun. He is the heat being lost, and your body is the mass paying the price to sustain his presence."
Oboro looked down at his own hands, which were glowing a faint, ghostly blue on the thermal monitor. "So I'm like a... a heat vampire? But I'm not doing it on purpose!”
“He says he’s not doing it on purpose,” Izuku repeated, his voice shaking so violently his teeth clattered.
"It is an involuntary biological—or metaphysical—tax," Nedzu replied.
Izuku paused, his brow furrowed as he tried to pull his thoughts through the mental fog of hypothermia. “But... how did he exist for so long without freezing Present Mic or Aizawa-sensei? He was following them for years. And why is it only happening to me now? For the past week, it’s just been... chilly. Like a drafty window and sometimes there’d be a strong breeze, but still, why the sudden jump?”
Nedzu tilted his head, his small paws coming together. "A sharp observation. Tell me, Midoriya-kun," Nedzu asked, his eyes glinting. "Has his ability to interact with you changed over the past few days?"
Izuku nodded slowly, his breath puffing out in a thick, white cloud. "At first, Oboro was just... there. He could move a pen or a notebook, and if he tried really hard and had some time to focus, he could pick up your… uh—files. He could also short-circuit tech. Two days ago, his hand phased through mine. It hurt—like a sharp sting—but I didn't freeze, or ice didn't form. It felt more like when your hand's super cold and then you go somewhere where it's warm. Like, your hand stings. I felt that and it was just colder afterward. But today..." Izuku to his blazer, afraid to find frost. "Today he grabbed my arm when he saw Aizawa-sensei. He gripped me. And that’s when the ice formed."
"There is your answer," Nedzu chirped, though his tone remained clinical. "Until recently, Shirakumo-kun was a passive observer—a radio signal with no speaker, per say. But he has spent the last week 'learning' how to interact with your specific frequency. Every time he moves an object or touches you, he is refining the connection. Two days ago, his hand passing through yours was an accidental discharge of energy. But a grip? A grip requires intent. It requires a massive influx of energy to stabilize his molecular structure against yours. The reason you didn't feel this with Aizawa or Yamada is that he never—to keep this radio metaphor going— ‘tuned in' to them.”
Oboro looked at his hands, his form shimmering with a guilty light. "I didn't know... I was just trying to help. I didn't realize that holding on meant taking something away."
"He was passive then," Izuku explained to the Principal, his voice growing softer as the exhaustion of the heat loss set in. "So—you’re saying he needs a power source?’
"Precisely," Nedzu said. "Participation has a high caloric cost. However, this danger provides us with a magnificent tool. If the Second Law of Thermodynamics holds true here, the amount of energy he needs to 'tether' to you should be proportional to the distance from his original physical coordinates."
Izuku rubbed his arms vigorously, trying to generate even a spark of friction. "You mean... if we get closer to wherever they're keeping his body, I'll stop being so cold?"
"Yes! Or at the very least, the 'signal' will be stronger, requiring less of your personal 'battery' to maintain the link," Nedzu chirped, his energy rising with scientific fervor. Man, he was scary."Conversely, the colder you get while stationary, the more 'work' he is doing to maintain his form against some kind of external interference. For instance, the 'static' Oboro has mentioned.”
Nedzu pulled up a map of Musutafu, overlaying it with the city's power grid. "For the past seven hours, I have been monitoring unusual spikes in energy consumption. Most high-level laboratories require massive amounts of cooling for biological storage. If we find a location that is pulling massive amounts of electricity to maintain a sub-zero environment—matching the 'cold' Shirakumo-kun remembers—and your own body temperature begins to stabilize as we approach it..."
"We find the lab," Izuku finished, his voice trembling but determined.
"And we find the rest of me," Oboro added, his form flickering into a more solid state as he flared with a sudden, desperate hope.
Nedzu hopped down from his chair, his movements purposeful. "But first, we must prevent you from reaching hypothermia. I’ll have a specialized support item in development—a localized heating vest powered by a high-density battery. You can fit it under both your uniform and your hero costume. It will provide an external ‘threshold’ for Shirakumo-kun to draw from so he stops eating your lunch, so to speak."
Nedzu paused at the door, his paw resting on the handle as he looked back at Izuku. The sharp, analytical gleam in his eyes softened just a fraction into something approaching empathy. "But be mindful, Midoriya-kun. Yes, I’ll make sure the vest is a masterpiece of thermal engineering, but there’s only so much science can do when it comes to the supernatural. It is a buffer, not a cure."
"I understand," Izuku said, his voice trembling slightly as he tried to suppress a shiver that started at his tailbone and vibrated through his teeth.
"The prototype is currently undergoing a final calibration in the Power Development Studio, I had figured something like this would occur," Nedzu continued, his mind already calculating the logistics. "The insulation needs to be perfect to ensure the battery's heat is directed inward toward your core rather than dissipating into the environment. I hope it will be ready for you tomorrow morning. Until then," he gestured to the door, "I suggest you find the warmest place in your dorms and stay there. Try to minimize Shirakumo-kun's physical manifestations."
Oboro drifted toward the floor, looking genuinely dejected. The vibrant blue of his hair seemed to dim. "I'll stay quiet, Izuku. I promise. I’ll just... hover in the corner like— a, uh, very still lamp—?"
"It's okay, Oboro, you don’t have to do that," Izuku whispered, his heart aching more than his frozen limbs. He turned back to Nedzu, bowing as deeply as his stiffening joints would allow. "Thank you, sir. For everything."
The walk back to Heights Alliance was no longer a simple commute; it was a trek through a private, localized arctic. Every time Oboro spoke or even shifted his weight in the air, Izuku felt a sharp, icy pull at his sternum, as if a needle were drawing heat directly from his heart.
By the time he reached the common room, the tips of his fingernails had faded to a ghostly, bruised blue. The realization hit him with the force of a blizzard: Why is this happening so suddenly? Even with the principal’s explanation, it felt too jarring. Or, more terrifyingly, did I just not notice? Looking back, he’d been freezing for a week, but he’d simply blamed the biting December frost.
"Whoa, Deku!" Uraraka’s voice sliced through his haze. She sat on the sofa, her smile vanishing instantly. "You look... really pale. Are you okay?"
"Just... the winter air," Izuku lied, his jaw locking to keep his teeth from clacking together. "Going to... hot shower. Turn in early. Remedial studies were... uh– intense."
He didn't wait for a response. He practically scrambled for the stairs, every step feeling like he was moving through thigh-high snow. Izuku wished people would stop bringing up his lack of body heat, it’s like they manifested it getting even worse.
Inside his dorm, the "pins and needles" sensation in his extremities had turned into a dull, throbbing ache. He cranked his space heater to the maximum setting, the orange coils glowing like a distant sun, and climbed into bed wearing three layers of sweaters. Oboro sat on the edge of the desk, looking like a flickering candle in the dark room, his blue hair casting a dim, melancholic light.
"I'm sorry," the ghost whispered, his voice sounding thinner than usual. "I’m causing you so much trouble.”
"It's not your fault," Izuku murmured into his pillow, his stomach feeling like a hollow ice block. "We just have to hold out until tomorrow. Once we have the vest, we can start looking for you. We can find where they're keeping your body."
Just as Izuku began to drift into a shallow, shivering sleep, a sharp, heavy knock sounded at his door. Three raps—precise, and utterly inescapable.
"Midoriya."
It was Aizawa. His voice was flat, but it carried that specific edge that meant he wasn't leaving until the door opened.
"I know you're in there. I just spoke with Present Mic. Open the door. We need to talk about why you felt like a block of ice in his classroom today."
Izuku’s heart plummeted. A spike of adrenaline, even colder than the hypothermia, momentarily cut through the sluggishness of his limbs. He looked at the door, then at Oboro, who was already retreating into the shadows near the closet, his form flickering with the same anxiety Izuku felt.
"Are you sure you can even get up?" Oboro whispered. "And even if you can, you sound like you’re talking through a mouthful of snow."
Izuku didn't answer. He scrambled to shove his notebook and the bag of tea cakes under his pillow. He didn't have time to stage a fake sleep—Aizawa was far too observant for that. Instead, he pulled his heaviest comforter around his shoulders like a shroud and shuffled toward the door, his legs feeling like leaden weights.
"Coming, Sensei," he called out. His voice was raspy—a thin, brittle sound that made him wince.
He cracked the door open just a few inches, making sure the security chain was taut. He stayed deep in the shadow of the doorframe, acutely aware that the small room was becoming a micro-climate of frost; he didn't want Aizawa seeing the faint white mist of his breath, which was puffing out in rhythmic, ghostly clouds.
Aizawa stood in the hall, his arms crossed over his chest. He looked tired—more tired than usual—but his eyes remained as sharp and predatory as a hawk’s. "Yamada-sensei says you were 'like ice’ today in his class. Why aren't you in the infirmary, Midoriya?"
"I'm... I'm just tired, sir," Izuku said, a shiver racking his frame despite his best efforts. The movement made the security chain rattle against the doorframe like a warning bell. "I think the walk back from the archives yesterday was just too much in the cold wind. I’ve been drinking tea and staying under the blankets. I'll be fine by morning."
Aizawa’s eyes narrowed. They dropped to Izuku’s hands, which were white-knuckled as they gripped the edge of the door. Even in the dim hallway light, the knuckles were a worrying shade of blue-white, the skin stretched thin over bone.
"Nedzu says you're on a special curriculum," Aizawa said, his voice dropping into a low, dangerous register that demanded the truth. "And now you're showing symptoms of a physiological drain I’ve only seen in high-intensity combat scenarios or severe Quirk-exhaustion. I’m not a fool, Midoriya. Something is taking a massive toll on you."
"Tell him you're practicing your Quirk or something," Oboro suggested from the dark corner. His voice was a faint whisper of static. "Give him a 'Hero' excuse!"
"It's... it's a new training method," Izuku blurted out, clinging to the skeletal lie Nedzu had provided as a safety net. "For my Quirk. It involves... internal temperature regulation. The theory is that my Quirk overloads my system with heat, so to compensate, I'm trying to see how low I can drop my core temperature to find a balance. I’m— uh, I’m still adjusting. Nedzu-sensei is monitoring the data."
Aizawa reached out, his hand stopping just short of the door. He seemed to be fighting the internal urge to reach through the gap and feel Izuku’s forehead. "If Nedzu is the one monitoring you, then why did he look surprised when I mentioned you were pale this afternoon?"
Izuku’s heart stopped. Aizawa was bluffing—or Nedzu had slipped up in a rare moment of oversight.
No, Nedzu wouldn't, Izuku thought, steeling his nerves. I trust that rat—shit! He’d just called the Principal a rat in his own head. Oboro’s terminology was clearly starting to rub off on him, even in the middle of a high-stakes interrogation.
"I... I hadn't told him the, uh, symptoms were starting t-tonight, sir," Izuku stammered, his breath visible as a silver plume in the hallway light. "I was going to report the shift in the morning."
"Go to sleep," Aizawa finally said, though the words sounded more like a warning than a directive. He lingered for a second longer, his eyes scanning the narrow slice of the room he could see. "But if your temperature hasn't returned to normal by homeroom, I’m personally taking you to Recovery Girl. And I’ll be asking for a full blood panel. I don't care what the Principal's curriculum says."
He turned and walked away, his footsteps heavy and echoing down the corridor.
Izuku closed the door and leaned his weight against it, sliding down until his tailbone hit the floor. He let out a long, shaky breath that felt like it was freezing the very air in front of his face. "That was... too close. Way too close."
Oboro drifted through the closet door, his expression heavy with a crushing weight of guilt. "He knows something is wrong, Izuku. I keep telling you—Shouta has always had a sixth sense for this kind of stuff. He can smell a lie from a mile away. And now I'm turning you into an icebox just by being near you. I'm hurting the person trying to help me."
Izuku gripped his knees, trying to force the tremors to stop, but his muscles felt like they were made of brittle wood. "We just have to make it to the morning. Once I get the vest from Nedzu, the 'remedial studies' excuse will actually have some teeth. It'll give us the heat we need to keep the link stable. We can do this, Oboro."
Izuku paused, the silence of the room feeling heavy and frigid, a stark reminder of the unnatural state he was in. He looked at his blue-tinged fingers and then at the shimmering, translucent boy beside him.
“We have to,” he repeated, his voice barely a whisper. “Because if we don’t find where they’re keeping you soon... I don’t think there’s going to be enough of me left to keep you here.”
“So, how’s the listener?” Hizashi asked from the couch. He wasn't wearing his glasses, and his long hair was tied back in a messy bun, making him look less like a radio personality and more like the worried husband he was. The apartment felt unnervingly quiet; the faculty had decided Eri should stay with Nemuri for a few days, reasoning that she could use a maternal presence as well as staying with Shouta. Plus, Nermuri’s Quirk would still be effective if Eri’s own power ever got out of hand and Shouta wasn’t nearby.”
Hizashi adjusted a cushion, his voice low. “Did you get a look at him? Is he actually sick, or just plowing his way into a burnout? Or... given what I felt earlier, would it be a freeze-out?”
“He’s in his room,” Shouta said, walking into the small living area. He dropped his capture scarf onto the side table with a heavy thud. “He claims he’s fine. Says he’s doing some ‘internal temperature regulation’ training for Nedzu.”
Hizashi frowned, leaning forward, his brow furrowed in genuine confusion. “Temperature regulation? Since when does his Quirk involve heat? I thought it was all power and speed.”
“It doesn’t,” Shouta replied flatly, his voice tight. “That’s the problem. He’s lying. Or rather, he’s being coached on what to say.” He ran a hand through his hair, pacing the small length of the rug like a caged animal. “He looked so cold, Hizashi. Like a— a corpse. If we were in the middle of a training session and I saw a student that gray, I would have called an ambulance on the spot.”
Hizashi’s expression darkened, the usual light in his eyes dimming. “Corpse cold? Well, if that isn’t a good way to describe what I felt in the classroom, then what is? It wasn't just a winter chill. It felt… wrong. Like something was sucking the heat right out of the air around him.”
Shouta stopped pacing and looked at his hands, still feeling the phantom frost from the door handle biting into his skin. “Nedzu is involved. He’s providing the cover story. Whatever Midoriya is doing, he’s doing it with the Principal’s blessing, which means I can’t officially intervene without a direct safety violation. Not yet.”
“But you’re going to watch him,” Hizashi said. It wasn’t a question; they had known each other far too long for it to be one.
“I’m going to watch him,” Shouta confirmed, his jaw set. “If he looks even a shade paler in homeroom tomorrow, I’m dragging him to the medical wing myself, Nedzu be damned. I won’t let one of my kids have his insides frozen and shriveled up on my watch.”
The room fell quiet, the air thick with the weight of unsaid things. Shouta finally sat next to Hizashi, taking the blonde's hand in his own and letting his head come to rest on his husband's shoulder. The tension in his spine didn't vanish, but it shifted, shared between the two of them in the quiet sanctuary of their home.
“He’s a good kid, Shouta,” Hizashi whispered, squeezing Shouta’s hand tight. “He’s got that same look in his eyes that Oboro used to get. You know the one—like he’s about to do something incredibly stupid, but for a reason so good you almost can’t argue with him. It's a terrifying kind of noble.”
Shouta winced at the name, the old wound twinged by the comparison. “That’s exactly what I’m afraid of. That kid has no sense of self-preservation when he’s a walking corpse. He doesn't know how to stop.”
Hizashi breathed out a sorrowful, brittle chuckle. He looked toward the darkened window, his voice turning soft and distant. “If Oboro were actually here right now... what do you think he’d say to the kid?”
Shouta closed his eyes, picturing a shock of blue hair and a crooked, confident grin that could light up a room. “He’d probably tell him to stop brooding and eat a damn tea cake,” Shouta murmured, a ghost of a smile touching his lips. “And then he’d jump right into whatever mess Midoriya is making, twice as fast and half as careful. He’d be his biggest cheerleader and his worst influence all at once.”
“I miss him,” Hizashi whispered. The words were raw, stripped of his usual radio-host vibrance, leaving only the ache of a decade-long absence.
Without a word, Shouta shifted, opening his arms. Hizashi leaned in, burying his face into the crook of Shouta’s neck, his breath warm against Shouta’s skin. It was a rare moment of total vulnerability, the kind they only allowed themselves within these four walls.
“I know,” Shouta said softly, resting his chin atop Hizashi’s head. He tightened his grip, anchored by the solid weight of his husband, trying to ward off the cold that seemed to be seeping into the room from the memory of Midoriya’s door. “I know.”
He didn't see the way the air in the center of the room suddenly shimmered, like light hitting a cloud of dust or the first sign of a storm. He didn't notice the way the temperature dropped just a fraction of a degree—not a biting, cadaverous chill, but a soft, fleeting pressure against his back, like a comforting hand.
For a heartbeat, the faint, impossible scent of ozone and summer rain lingered in the air, as if a ghost were leaning in to listen, resting an invisible hand over theirs before fading back into the shadows of the apartment, leaving only the warmth of a shared memory behind.