Today, I went alone to a department store to buy a birthday present for Eiri.

  She’d moved to Tokyo a year before me. Up until early spring, she used to message me all the time. But lately—nothing. No replies, no read receipts. I couldn’t even bring myself to ask why. The silence just piled up in my chest, heavy and slow.

  Halfway up the stairs, I stopped.

  The steps were polished marble. Embedded in the white stone was a dark swirl, like a shadow caught mid-spin.

  An ammonite.

  A fossil, spiral-shelled, sleeping in the “strata” of the staircase as if it had always belonged there. Millions of years of ancient seabed, sealed inside a city department store.

  The absurdity of it made something in my gut twitch.

  “…That’s incredible,” I murmured.

  And right then, in the corner of my vision, something yellow wavered.

  A tiny light floated up—soft, weightless—and vanished.

  “Huh…?”

  For a second, my mind reached for the simplest answer.

  A firefly.

  I remembered how department stores used to sell beetles and stag beetles for kids in summer. Maybe they still did. Maybe one had escaped.

  But this was winter. And this was the third floor. There was no way.

  Then my brain offered another explanation: those insect-shaped drones people played with. Still—under these bright lights, how could a glow stand out?

  I tried to track it with my eyes, but the light snuffed out in an instant. When I looked again, there was nothing at all.

  My eyesight isn’t great. At the time, I told myself it was probably just a trick of reflection—an afterimage, a mistake.

  Still… the “afterimage” stayed with me.

  I went to the accessories floor and chose a small bracelet with a pale green stone—subtle, gentle, the kind of color Eiri liked. Even while I waited for it to be wrapped, the memory of that light kept sticking to the inside of my skull.

  No. I thought.

  That was a firefly.

  When the clerk handed me the wrapped box, I took one deep breath and stepped outside.

  In the thin dusk, the wind carried a brief, impossible hint of spring.

  Like the seasons are mixing, I thought, and the unease that had been building all day quietly swelled.

  Eiri’s apartment wasn’t far. Her uncle owned the building—she’d told me that early on—and I’d visited before, more than once.

  Even so, that night the distance felt wrong. Too long. Too far. Like the streets had been stretched when I wasn’t looking.

  The borders between lamplight and shadow felt unstable, as if the world couldn’t decide where anything belonged. My steps kept drifting.

  The wind was cold enough to sting my cheeks, but the ache inside my chest hurt more.

  I rang the doorbell.

  After a moment, the door opened, and warm air spilled out into the corridor.

  Eiri stood there.

  For the briefest instant she looked startled to see me. Then the surprise hardened into something guarded.

  “…Naoto? What are you doing here?”

  She said my name, but there was no warmth in it. No nostalgia. It sounded… off, like a chord that didn’t quite resolve.

  “It’s your birthday,” I said. The words came out like excuses even to my own ears. “I brought you something. And… you haven’t been replying lately, so I—”

  I held out the bracelet box.

  It felt strangely light in my hand, like it didn’t contain anything at all.

  Eiri stared at it, then faintly furrowed her brow.

  “Naoto…” she said, voice steady. “Didn’t I tell you to stop doing this?”

  “…What?”

  “You and I were senpai and kohai—upperclassman and underclassman. That’s all we ever were.”

  The sentence slid into my ribs like a cold blade.

  I inhaled sharply without meaning to.

  “But—why? Why all of a sudden?”

  Eiri looked away.

  The moment she did, it felt like I’d been cut loose from the world. Like the room had closed around her and left me outside.

  “Naoto,” she said, serious—still using the calm, polite tone I remembered. “You’re a kind person. But after we were apart, I realized something. Sometimes that kindness… feels heavy. And the reason I stopped leaving read receipts…”

  She met my eyes for just a second.

  “Honestly, I wanted distance.”

  The softness of her voice made it worse, not better. It crushed me with how reasonable it sounded.

  Somewhere inside me, something began to set and harden—slowly—like an ammonite turning into stone.

  Her phone vibrated.

  “…Sorry.” She glanced at the screen.

  And for a split second, her expression brightened—just a flicker, but unmistakable.

  A name I didn’t recognize flashed on the display.

  Still facing away from me, Eiri swiped to answer.

  “Yeah… I’m coming out now. No, it’s fine. I’ll be right there!”

  That voice—so gentle, so bright—was softer than anything she’d ever used on me.

  Something in my chest came apart. Not in one clean break, but with a quiet, crumbling sound.

  I couldn’t stay there. I turned for the entryway.

  “Naoto…”

  She called after me, and my whole body flinched.

  For one terrible moment I wanted to cling to that sound, to believe it meant something.

  “…I’m glad I got to see you one last time,” she said.

  It was kind. It was gentle.

  And it didn’t feel like it was meant for me.

  It felt like she was saying goodbye to an old version of me—someone who no longer existed.

  I shut the door.

  Outside, the air was even colder. My breath whitened immediately.

  I wasn’t sure where I was standing in my own life anymore.

  And then—in the snow—a small yellow light fluttered.

  A firefly.

  A glow that shouldn’t exist in winter.

  It drifted forward, further and further ahead of me, like it was trying to show me what came next.

  “…What the hell is this?” I whispered.

  Even as I spoke, I followed it.

  I had no other reason to keep walking.

  The firefly flashed, leading me down a snowy night road.

  And my feet—without hesitation—went after it.

  At some point, I stopped knowing where I was.

  I only knew that I couldn’t let that light leave me behind. That stubborn, stupid urgency was the only thing pushing my legs forward.

  The city night felt buried under snow. Sound was being swallowed, packed down. For Tokyo, it was too quiet. Too wrong.

  Then the feel under my shoes changed.

  It stopped being asphalt.

  This story has been stolen from Royal Road. If you read it on Amazon, please report it

  A dry branch snapped with a thin, brittle sound.

  I froze.

  “…A forest?”

  There was no city here. No streetlights. No cars. No people.

  Snow-laden trees surrounded me in silence.

  I couldn’t accept it. A minute ago, I’d been walking through a residential area—not crowded, but normal. The kind of place where you could still hear distant traffic.

  Following a tiny light shouldn’t have taken me somewhere like this.

  And yet the scene in front of me felt brutally real.

  I exhaled and stepped forward.

  The deeper I went, the colder it got. The edges of the world seemed to thin, like the outline of everything was fading. Branches bowed under snow and trembled quietly.

  It reminded me of winter mountains back home.

  After a while, the trees opened up.

  In the center of a clearing lay a spring, glowing faintly blue-white.

  The surface was completely frozen.

  Thin layers of ice overlapped, catching moonlight and shining like stacked glass.

  The firefly drifted to the middle, flared once—bright—and vanished.

  Even after the light disappeared, my gaze stayed fixed on the center of the ice.

  Because I realized something was there.

  A shape under the frozen surface.

  “…What?”

  My voice came out as a breath.

  Under the ice, beneath the dark water, a woman lay on her back.

  She wore a white dress.

  Her hair floated lazily, suspended as if the water itself had fallen asleep. Her clothes blurred faintly, like they were swallowing light.

  Her eyes looked closed.

  Was she sleeping?

  Was she dead?

  I couldn’t tell where that boundary was anymore.

  A shiver ran through my spine that had nothing to do with cold. My throat tightened like it had iced over.

  The fear wasn’t sharp—it was vast. Like being left behind by the world.

  I staggered back.

  Then, deeper in the forest, a branch snapped.

  Someone was there.

  No—something.

  I couldn’t stay. I turned and ran, away from the spring, away from the ice, away from the woman who might not have been a woman.

  Each step on the snow made a wet sound.

  I ran until I didn’t know how long I’d been running. My lungs burned. My chest creaked with every breath.

  Then the air changed.

  The winter smell thinned. In its place came damp, heavy heat—the scent of summer.

  Moist air clung to my skin. Under my winter clothes, I began to sweat like I’d stepped into a sauna.

  “…Summer?”

  I stopped, spinning in place.

  The trees were different—lush, thick, alive. The ground smelled of warm earth, not frozen soil.

  And above the river ahead, countless lights drifted through the dark.

  Fireflies.

  “So many…” I whispered. “Genji fireflies?”

  This wasn’t a winter forest.

  It was the height of summer on a riverbank.

  The season had been swapped out whole, as if someone had flipped a page in reality.

  I stood there, unable to move.

  The boundary between dream and waking blurred until it didn’t matter anymore. Even the feeling in my feet wouldn’t settle.

  Where was I?

  Was this the continuation of that spring?

  Or had I fallen into another time entirely?

  The fireflies’ glow flowed toward the river like a current of light.

  And from that direction, I heard voices—an argument.

  I started walking as if pulled.

  As I followed the lights, the humid night air clung to my throat. Under my winter clothes, my undershirt was soaked. My body still remembered sprinting through snow, and it couldn’t reconcile the heat.

  I peeled off my jacket as I approached the water.

  The voices became clear.

  “I can’t do this anymore! I told you—I can’t!”

  A woman’s voice. Shaking, but threaded with anger she’d been holding down too long.

  “Don’t talk like that! You think you get to decide? After everything I—”

  A man’s voice, rough, maybe drunk.

  I pushed through the trees and saw them on the moonlit riverbank.

  The fireflies cast a soft, floating light around them, turning the scene into a stage cut out of the night.

  The woman wore a light summer kimono—a yukata—her hair disheveled. The man wore a T-shirt, his face flushed.

  “Let go—you're hurting me!”

  As the woman tried to shake him off, the man stumbled, irritation snapping into rage.

  “It’s your fault…!”

  His hand slid into his pocket.

  Something in my gut warned me before my brain fully caught up.

  Moonlight flashed on metal.

  A blade.

  “Stop!”

  I was already shouting before I realized I’d moved.

  My body acted first. I kicked off the dirt and slammed into the man with everything I had.

  The impact jolted through both of us. The knife flew from his hand.

  The next instant, we tumbled into the river.

  Cold water punched into my lungs. The world spun. I flailed, fighting to surface.

  The man roared and grabbed for me, trying to drag me down with him.

  I thrashed toward the shore, hands clawing at water, legs kicking uselessly.

  I don’t know how I made it.

  When I finally hauled myself onto the bank, my whole body shook uncontrollably.

  The woman ran over.

  “A-are you okay?” she asked.

  Tear tracks cut down her cheeks. Fear and relief tangled in her face.

  I forced air into my lungs and checked the rhythm of my heart like it was the only thing keeping me here.

  “Yeah,” I managed. “I’m okay. We should call the police…”

  I reached for my phone.

  And the moment I did, my vision lurched.

  The fireflies’ lights blurred into a ring around me, as if they were circling.

  “—Thank you,” the woman said, her voice already growing distant. “Really… thank you.”

  The earth under my back felt strangely cold for a summer night.

  And then my consciousness sank, straight down, into black.

  Someone was shaking my shoulder.

  I gasped, and something inside my chest felt like it tore.

  “…Are you okay?” a woman asked.

  I coughed, choking on air that was too dry, too clean.

  For a second, I could still hear the river in my ears—the hush and pull of running water—but the voice beside me was crisp.

  When I opened my eyes, I wasn’t on a riverbank.

  I was on the Shinkansen—Japan’s bullet train.

  The soft upholstery pressed against my back. The train’s metallic vibration pulsed in a steady rhythm. Outside the window, darkness streaked by at speed.

  “You were really… having a nightmare,” the woman sitting beside me said, looking worried. “You looked like you couldn’t breathe.”

  I blinked over and over, trying to make the scene lock into place.

  My body was dry.

  There was no wet clothing. No river stink. No grit under my nails.

  My hands were clean.

  Was it a dream?

  I pressed a palm to my chest. My heart was still racing, too fast for a dream that had ended.

  “Um… where are you headed?” the woman asked gently.

  Reflex answered for me.

  “…Tokyo.”

  The word came out so naturally it startled me.

  Then, in the next breath, the wrongness hit.

  I yanked out my phone.

  Time. Date.

  My fingers went cold.

  Yesterday.

  The date was the day before I went to the department store.

  Before I saw the firefly. Before the forest. Before the river.

  I could barely breathe.

  All the sensations—ice, water, humid air—had vanished as if they’d never existed.

  Only the memory remained, vivid and sharp.

  “…Are you sure you’re okay?” the woman asked again. “You looked like you were trying to scream. I couldn’t make out the words.”

  I nodded small and stiff.

  “Sorry,” I said. “Just… a weird dream.”

  It wasn’t a dream.

  Some part of me knew that with the quiet certainty of a bruise.

  But I couldn’t explain it. Not to her. Not to anyone.

  The announcement chimed. The train began to slow. Soon the station. Soon the platform.

  I stood, legs unsteady, and stepped out into winter air that smelled exactly like it had yesterday.

  Yeah.

  This wasn’t something my brain had invented.

  I had lived it.

  And another thought stuck even harder than that:

  the woman on the riverbank.

  Her tearful “thank you” wouldn’t leave my ears.

  Was that real too?

  Or—ridiculous as it sounded—had it been something that happened on a different timeline, one my life had brushed against for a single night?

  I inhaled slowly.

  Whatever it was, the world had started again like nothing happened.

  And I was expected to pretend along with it.

  After that, Eiri and I ended quietly.

  On her next birthday she greeted me with a brightness that almost convinced me I’d imagined everything. Almost.

  Messages got answered again. Read receipts returned. But the distance never did.

  The breakup itself took one short conversation.

  What stayed with me wasn’t her last words. It was the woman on the river, crying as she whispered, “Thank you.”

  Was it really a dream?

  That question didn’t fade. It gained weight as the seasons turned.

  Then summer came. Humidity wrapped the streets, and one day the river surfaced in my mind again, clear as if it had been waiting.

  I searched online for “firefly river famous spot” and found a place listed as a local attraction.

  The photos looked too much like my memory.

  My chest tightened.

  I bought a ticket and went without hesitation.

  I got off at a station, walked down a quiet road, and felt damp wind brush my skin. From far away came the sound of running water.

  Then, through the trees, I saw it—

  countless pale lights hovering over the river.

  Fireflies.

  Just like that night.

  I stood there, unable to move for a while, breathing until my heart stopped trying to climb out of my ribs.

  It felt like the lights had called me back across time.

  Then—

  “...Huh?”

  A voice behind me.

  I turned.

  A woman in a yukata stood there. Pale yellow fabric, small flower patterns scattered across it.

  The moment I saw her face, I forgot how to breathe.

  It was her.

  The woman who had cried in the dark, who had whispered thank you to me by the river.

  She looked hesitant, a little confused—and at the same time, like she was recognizing something she couldn’t quite name.

  “…It really is you, Naoto-san, right?”

  I stared.

  How did she know my name?

  I didn’t understand any of it, and yet a quiet certainty rose anyway.

  She remembered.

  She remembered that night too.

  “It’s been a while,” she said softly, smiling as if testing the truth of it. “It feels weird to say, but… it really has.”

  Something inside my chest loosened. Not all at once—just enough to breathe.

  I nodded slowly.

  “I… had a feeling if I came, I’d see you.”

  It wasn’t a complete explanation. Not even close.

  I hadn’t come “for her” exactly. I’d come to confirm my memory. To prove I wasn’t losing my mind.

  But the way her eyes softened made it feel, for a second, like the universe had given me a reason anyway.

  “I come here every year,” she said, looking out over the river. “When I’m lost. When I’m feeling down. This place… calms me.”

  Fireflies drifted over the water, scattering their light like gentle sparks.

  “…That night,” she said, voice quieter, “you really saved me, didn’t you?”

  Her tone still carried a faint tremor of that fear.

  I opened my mouth, then stopped. What was I supposed to say?

  That winter became summer.

  That the world folded.

  That I’d seen a woman under ice.

  If I said it out loud, I was afraid the memory would turn into a lie.

  But she was standing here, right in front of me, remembering too.

  “I don’t think it was a dream,” I said finally. “I… couldn’t make myself believe it was.”

  Her breath caught.

  Just that reaction was answer enough.

  “…Me neither,” she whispered. “I think it was real.”

  Her voice shook, but it wasn’t only fear. There was steadiness in it too—the kind that comes from surviving.

  “When you disappeared,” she said, eyes fixed on the water, “I didn’t understand. I didn’t know where you went. But being able to say thank you… that felt like a miracle.”

  Then she glanced back at me, and her smile was gentle.

  “I thought… if I came here, maybe I’d meet you again. So I came this year too.”

  Warmth rose into my chest, bright and painful.

  The river flowed, calm and steady, carrying the past without sinking under it.

  “I’m glad you’re okay,” I said.

  “And I’m glad you’re here,” she replied.

  We walked along the river together.

  My steps were slower than usual. I noticed it and couldn’t help it. It felt like if I rushed, I might shatter the moment.

  Above the water, fireflies drew faint trails and dissolved, over and over, like threads tying one night to another.

  “This river really is peaceful,” she said.

  “Yeah,” I murmured.

  The air was soft. No shouting. No blade. No panic. Just night wind brushing our cheeks.

  “I keep thinking about that night,” I admitted. “About what I saw.”

  She stopped and looked at me. Firefly light trembled in her eyes.

  “What did you see?” she asked, quietly.

  I hesitated.

  Winter forest. Frozen spring. A woman under ice.

  The words pressed against my teeth like a secret that wanted to be let out.

  “It’s hard to put into language,” I said. “But… it felt like I saw the moment the seasons switch. Like a door opening and closing. Suddenly I didn’t know where I was, and everything was wrong. But… if that hadn’t happened, I don’t think I would’ve reached you.”

  She nodded slowly.

  “Maybe those things can happen,” she said, as if she was choosing to accept the impossible. “It sounds unreal, but… you’re right. No matter how strange it was, I’m alive because of it.”

  She smiled again.

  This wasn’t the tear-streaked face from that night.

  It was the face of someone living in the present.

  “Can I… come again?” I asked before I could overthink it.

  It surprised even me.

  She blinked, then her expression softened.

  “Yes,” she said. “I’d like that. I want to see you again too.”

  We kept walking side by side.

  Somewhere overhead, stars glittered.

  A firefly drifted close, crossed between us, and scattered a faint light as it passed—then vanished into the summer dark.

  I watched it until it disappeared completely.

  The glowing path it left behind looked like a thin thread—connecting memory to reality, loss to something you could hold.

  Maybe a firefly never flies the same route twice.

  Even so…

  That light had brought us here.

  And as the river continued to flow, I thought:

  It wasn’t guiding me across the border of seasons.

  It came to hand me back something I was about to lose.

  Across the river, beneath the firefly-lit surface, something pale shifted—like a face turning in the dark. Then the water stilled, and the lights kept drifting.