Work Text:
Baek Kanghyuk had lived in this apartment block for three years. Three years of routine. Coffee before work, hospital shifts, medical journals at night, lights out by midnight. His window was nothing more than a rectangle of glass — good for gauging the weather or letting in some air. He never once thought it could matter.
Until that evening.
He was rinsing out his mug, hair damp from a late shower, when movement flickered in the opposite apartment. The curtains, usually drawn, fluttered open. A light switched on. And there — framed perfectly by the glow — was someone new.
Kanghyuk stopped breathing.
The boy was unpacking boxes, muttering to himself, hair falling into his eyes. He wrestled with a crooked lamp, grimacing when it leaned stubbornly, then laughed at his own struggle. A soundless, bright laugh that lit up his entire face.
Kanghyuk’s fingers went slack on the mug. He barely caught it before it slipped into the sink.
What… what is that face?
The thought was ridiculous, uncharacteristic, and yet it slammed into him with all the subtlety of a defibrillator. His pulse leapt, too fast, too unfamiliar. He swallowed hard, trying to force himself to look away, to return to his very normal, very ordinary evening.
But his eyes stayed fixed.
There was something otherworldly about it, something he couldn’t explain. As if a fragment of the moon had casually decided to take residence right across from him. And Kanghyuk, usually so stoic, so immovable, stood frozen with wet hair and a useless mug in his hand, struck dumb by the sight.
Stop staring. He’s just a new neighbor. This is nothing.
He tore his gaze back to his counter, cleared his throat, and tried to refocus. Thirty seconds later, his eyes flicked back of their own accord.
The boy — still smiling faintly to himself — was now arranging small potted plants on his windowsill. He tilted his head while adjusting them, tongue poking out slightly in concentration, before stepping back and nodding, satisfied.
Kanghyuk gripped the edge of his counter. His heart gave a traitorous little skip.
…Okay. Not nothing.
The boy yawned, stretched, then flopped down onto his couch, limbs sprawled. The glow of the lamp softened against his face, turning him into something dreamlike.
And Kanghyuk, who had survived night shifts, traumas, and endless adrenaline-fueled surgeries, felt his chest tighten in a way he couldn’t define.
For the first time in years, his apartment window wasn’t just glass anymore. It was a stage. And across that stage lived a boy who — in one glimpse — had turned Baek Kanghyuk’s ordinary evening into something quietly extraordinary.
Kanghyuk exhaled, defeated, a hand pressing over his racing pulse.
“…Great,” he muttered, almost laughing at himself. “I live opposite a celestial phenomenon. Perfect.”
But he didn’t look away. Not even once.
At first, Baek Kanghyuk convinced himself it was coincidence. He only happened to glance out the window, and there that boy was. Nothing unusual about it. He wasn’t waiting. He wasn’t curious. Absolutely not.
And yet…
Every evening, without planning to, Kanghyuk found himself at his desk by the window when the lights opposite flickered on. He’d pretend to read, a journal propped open in front of him, pen in hand. But the words on the page blurred, the ink pooled in idle doodles. His eyes, traitorous things, always drifted upward.
There he was again.
The boy — no, the moonlit figure — moving about as if unaware of his audience. Sometimes humming as he watered his little plants. Sometimes tugging a blanket around his shoulders, curling up with a bowl of instant noodles and the softest grin. Sometimes collapsing onto the couch, messy hair falling over his forehead, looking so alive, so unstudied, it left Kanghyuk’s chest tight.
Kanghyuk scolded himself nightly. You’re ridiculous. You’re too old for this. Stop staring like some infatuated schoolboy.
And yet the truth pressed in with every passing day: something about this neighbor was undoing him.
The first time it rained, Kanghyuk thought he’d keep his mind busy with paperwork. But then he heard it — the patter against his own window — and glanced up. Across the street, through streaks of water, the boy stood bathed in lamplight. A hoodie hung loose around his shoulders, and his palm rested gently against the glass as if he could feel the storm through it.
Kanghyuk forgot how to breathe.
The rain blurred everything except that face, soft and still, looking out into the downpour with quiet wonder. It was such a simple sight, and yet it carved something permanent inside him.
He sat there, unmoving, heart pounding like a fool.
What is this? Why does it hurt and heal at the same time?
When the thunder rolled, the boy startled and laughed at himself, small and sheepish. Kanghyuk pressed his knuckles against his mouth to stifle his own chuckle, feeling suddenly seventeen again, caught in a first crush that refused to be ignored.
The days blurred after that. He no longer noticed how late he stayed up. He no longer minded the silence of his apartment. Because in that rectangle of glass across the way, life unfolded like a private play performed only for him.
Every glance carried a weight he refused to name. Every absentminded smile from the boy felt like it belonged to him alone. And every night, Kanghyuk found himself reaching to switch on his lamp… only to stop. He didn’t need it. The light across the way was more than enough.
But always, always, he shook his head after, leaning back in his chair with a groan.
Hopeless. Absolutely hopeless. This isn’t real. He doesn’t even know you exist.
Still, when he closed his eyes, the image lingered. A mischievous grin. A gentle hand brushing hair back. A laugh too bright for its own good.
Baek Kanghyuk, surgeon, rationalist, skeptic of sentimentality, had stumbled into something he couldn’t name and couldn’t fight.
And no matter how many times he told himself otherwise, every evening ended the same way:
There, across the window, lived the piece of moonlight he hadn’t known he was waiting for.
Baek Kanghyuk prided himself on being a man of discipline. He could pull thirty-hour shifts and still wake at dawn sharp. He could sleep anywhere — in an on-call room, in the staff lounge, even on a hard hospital bench — if duty required it.
And yet, since that window lit up opposite his own, sleep had deserted him.
Every night was the same. He would shut his laptop, tell himself sternly: Bed. Now. Enough nonsense. He would brush his teeth, fold his arms, and lie down in the dark like a responsible adult.
Five minutes later, his eyes would slide open. His heart would thump like a drum against his ribs.
Is the light still on across the way? Just one peek. One. That’s it.
He’d groan at himself, roll onto his side, and fail spectacularly. Because the next thing he knew, he was standing at the window again, arms folded tightly as if he could strangle the feeling right out of his chest.
And there the boy would be. Sitting cross-legged on his couch with headphones in, nodding along to music. Or balancing a spoon like a microphone, mouthing lyrics with dramatic flair, laughing at his own theatrics. Once, he even twirled around with a broom as if the tiny living room was his stage.
Kanghyuk slapped a hand over his face, mortified at the grin threatening to escape him. Unbelievable. You’re a grown man, not a schoolboy spying on his first crush.
But even thinking the word crush sent heat racing up his neck. He dragged himself away, pacing the apartment, muttering under his breath.
“Ridiculous. Utterly ridiculous. This is just—this is… insomnia. That’s all.”
Insomnia that made him lie awake until two in the morning, staring at his ceiling, replaying every grin, every little shake of the boy’s head, every animated gesture. Insomnia that made him kick off his blanket in frustration, then pull it back on, then kick it off again. Insomnia that made him bury his burning face into his pillow like some teenager fresh from confessing his first love.
The next morning, he caught sight of himself in the mirror — dark circles, hair a mess, lips pressed tight in disbelief.
“Pathetic,” he muttered at his reflection. “You’ve assisted in open-heart surgeries, but you can’t handle a neighbor across the street?”
Still, the very same evening, he found himself back at the window. As if drawn by an invisible thread.
And when the boy leaned back, laughing at something on his phone, Kanghyuk’s heart fluttered so wildly he had to grip the windowsill to steady himself.
Hopeless. Absolutely hopeless.
But deep inside, he knew the truth: for the first time in years, he felt alive in a way he didn’t dare name.
Baek Kanghyuk had never considered himself a man easily swayed by appearances. In fact, he often scoffed at his colleagues’ idle chatter about looks, choosing to focus on skill, competence, and quiet discipline. He respected steadiness, calm, and strength. That was who he was. That was the kind of life he led.
And yet—
He could no longer deny the simple truth staring back at him night after night: the neighbor across the way was nothing short of breathtaking.
It wasn’t just the clean lines of his jaw or the way his smile tipped sideways, playful and effortless. It wasn’t only the delicate arch of his brows, or the brightness that lingered in his eyes as though they carried entire constellations in them. It wasn’t even the soft tumble of hair that seemed determined to fall into his gaze no matter how often he brushed it back.
It was everything. The whole of him.
Jaewon was beauty alive — the kind that didn’t shout for attention, but simply was.
Sometimes, he’d lean forward on the window sill, cheek resting against his palm, utterly unguarded. And in those moments, he seemed less like a boy in an ordinary apartment and more like a piece of moonlight, too tender and radiant for someone like Kanghyuk to stare at so greedily.
Other times, the simplest of gestures — laughing at something on his phone, tugging a hoodie over his head, squinting into the distance as if lost in thought — all of it left Kanghyuk’s pulse racing as though he’d been caught stealing a secret.
He pressed his forehead against the cool glass of his own window, sighing heavily.
“This is absurd,” he whispered to himself. “You’re turning poetic over a neighbor. Snap out of it.”
But he couldn’t. He was in too deep.
He thought of the night before, when Jaewon had tried to balance a book on his head, failed miserably, and collapsed into laughter that lit up the room like sunrise. Kanghyuk had clutched his chest in silence, horrified by how much he wanted to commit that sound to memory forever.
And then, last evening, the boy had opened the window just a crack, letting the breeze lift the edges of his shirt while he leaned against the frame with an expression of contentment. For Kanghyuk, that single image had been enough to undo an entire day’s worth of composure.
Because what could he possibly do with the knowledge that someone across the street could look so impossibly, carelessly beautiful?
He dragged a hand down his face. You’re lost. Entirely lost. And for what? A smile you’ve never even been given? A face that doesn’t even know yours exists?
And yet, despite the reprimands, the denial, the shame burning in his chest — his lips betrayed him. Softly, unbidden, they curved upward.
Because the truth was, no matter how much he tried to resist, every evening brought him back to the same place: waiting for that window to light up, waiting for the face that had begun to live in his heart as though it belonged there all along.
Baek Kanghyuk had always trusted in the quiet order of his life. Work. Rest. Work again. He didn’t ask for much more than that.
But lately, that order had been reduced to chaos.
Every evening, as the sun dipped low and the city lights flickered awake, his own chest flickered, too — in anticipation. He didn’t even pretend anymore. Dinner plates sat untouched. His books remained unopened. All he did was wait. For the faint glow across the street, for the faintest shift of movement, for the boy who had stolen the rhythm of his days without even trying.
And then, when Jaewon finally appeared, Kanghyuk’s composure shattered with painful ease.
Tonight, Jaewon had his hair damp from a shower, clinging in soft waves to his forehead. He wore an oversized sweatshirt, sleeves falling past his fingers, as if he’d borrowed something too big on purpose. He padded around barefoot, humming along to some tune only he could hear.
Kanghyuk’s heart clenched so tightly it was almost unbearable.
He gripped the edge of the window, trying to steady himself. This is dangerous. This is ridiculous. You can’t keep doing this.
But the denial rang hollow now.
Because it wasn’t just a passing fancy. It wasn’t simply boredom or neighborly curiosity. It wasn’t even the fleeting attraction he’d once scoffed at his colleagues for.
It was the way his heart leapt into his throat whenever Jaewon laughed — as if the world had been waiting to echo that sound. It was the way his gaze softened without permission, whenever Jaewon leaned sleepily against his couch or rubbed his eyes like a child. It was the way Kanghyuk found himself smiling, real smiles that startled him, simply because Jaewon existed within his line of sight.
And it was the way he missed him when the window was dark, as though something vital had been taken away.
He pressed a palm against his chest, horrified to feel the rapid hammering beneath it. Hopeless. Entirely hopeless. You’re in love, Baek Kanghyuk. You fool. You absolute fool.
But even as he scolded himself, something inside him gave way — like surrender.
Because wasn’t this what he’d been unconsciously longing for all along? That pull, that ache, that soft ache that made him feel alive again after years of numb routine?
He thought of all the nights he’d stayed awake, the countless times he’d lectured himself, the embarrassment of smiling into his pillow like some smitten teenager. All of it, every denial and every attempt at logic, had led him here.
And here was simple: he was in love. Pathetically, hopelessly, wonderfully in love.
For once, Kanghyuk didn’t fight the truth.
Instead, he let it wash over him. He let his heart beat too fast, let his palms sweat, let his lips curve into that small, secret smile. Because across the way, framed in the glow of his little apartment, Jaewon leaned into his window sill with his chin in his palm, gazing out at the night sky.
Kanghyuk whispered into the empty room, his voice barely a breath: “Beautiful.”
And for the first time, the word didn’t feel embarrassing. It felt right.
It had been one of those strangely quiet evenings.
The hospital had not called him in. His phone had not rung. Even the city beyond his window seemed to have hushed itself, as if it too was waiting for something.
Baek Kanghyuk sat at his desk, pretending to look at papers he hadn’t read in days. His pen twirled uselessly between his fingers. His eyes, of course, betrayed him — flicking, again and again, to that window across the street.
And then, like a star nudging its way into a dark sky, Jaewon appeared.
He tugged his curtains halfway open, yawning as if just waking from a nap. His hair was ruffled in the most disarming way, sticking up in soft tufts that somehow made Kanghyuk’s chest hurt with fondness. He wore a loose white T-shirt, sleeves falling to his elbows, fabric clinging gently where damp hair had dripped onto his shoulders.
Kanghyuk froze, pen mid-spin, breath caught.
There he was. The boy who had become his private universe. The one whose presence had rearranged his entire heartbeat.
Jaewon wandered about his living room, stretching his arms overhead, rubbing at his eyes, making little faces at nothing in particular — the small, unconscious kind that no one else would notice. But Kanghyuk noticed. He noticed everything.
His gaze softened without his permission. His lips curved into the faintest, helpless smile. And then, to his horror, he realized he was leaning forward on his desk, chin balanced in his palm, gazing as if he’d been painting Jaewon with his eyes.
Stop. You’re obvious. If anyone could see you now—
The thought broke off when Jaewon suddenly drifted toward the window.
Kanghyuk’s entire body went stiff. His heart gave a violent thud, like a gavel striking against his ribs.
No. No, no. Don’t look this way. Please don’t—
But Jaewon did.
He lifted his head, eyes sweeping idly across the street — and landed directly on Kanghyuk.
For a suspended second, Kanghyuk forgot how to breathe. He had been caught red-handed, like a child stealing sweets. Every instinct screamed at him to duck, to pretend he hadn’t been staring, to escape the humiliation of exposure.
But then it happened.
Jaewon smiled.
Not the casual kind tossed to strangers. Not the polite kind offered in passing. This smile was soft, deliberate, blooming slowly like a secret unfurling. His lips curved gently, his eyes warmed with quiet amusement, and there was something luminous about it — as if the moon itself had bent close and chosen to shine only for Kanghyuk.
The effect was catastrophic.
Kanghyuk’s pulse skyrocketed, his chest too tight, palms clammy, ears burning scarlet. His mouth went dry, but his heart… his heart was all chaos, drumming so wildly he thought surely Jaewon could hear it across the street.
And then Jaewon mouthed something simple, something that sent Kanghyuk spiraling.
“Hi.”
The tiniest syllable. But spoken with that smile, it felt like the world’s most precious gift.
Kanghyuk’s brain short-circuited. His body jolted with the sheer weight of the moment. For one dizzying instant he considered bolting from the room entirely, but his legs were rooted to the floor.
Instead, he swallowed hard, his throat dry, and somehow forced the word out — stammering, breathless, softer than he meant, but real.
“H… hello.”
The syllables stumbled from him like a confession. His cheeks burned hot, his eyes darted down, then back up again despite himself. He had never been so flustered in his life — not during a crowded surgery, not during a lecture, not ever.
But across the way, Jaewon’s smile only deepened, warm and unshaken, as if he found Kanghyuk’s awkwardness endearing rather than embarrassing.
Kanghyuk pressed his palm against his chest, desperately trying to steady his erratic heart. His mind screamed Hopeless. You’re utterly hopeless.
And yet, for the first time, he didn’t care.
Because the boy in the opposite window had seen him. Truly seen him. And smiled anyway.
And in that moment, beneath the soft glow of the city night, with two windows between them and an ocean of unspoken feelings, Baek Kanghyuk knew: his life had already changed.
All it had taken was one smile. One word. One moonlit boy across the way.