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Mafuyu greeted her mother quietly as she set her backpack down, the familiar weight slipping from her shoulder with a dull thud against the entryway floor. She knelt to untie her shoes, fingers stiff from the cold, when her mother’s voice drifted from the living room—light, cheerful, and slightly too practiced.
“Ah! Mafuyu, how was school today?” her mother asked with a smile that didn’t quite touch her eyes. The mismatch sent a faint prickle across Mafuyu’s skin. The room was unusually warm—almost stifling—and yet, somehow, the heat didn’t settle into her bones. Her bangs clung damp against her forehead, and the collar of her school uniform felt tight, as if it were shrinking around her throat. She nodded in response, though the motion felt hollow, like she was imitating herself.
Before Mafuyu could even part her lips to answer, her mother continued, turning away as she walked toward the couch.
“You have those practice tests coming up to see if you’ll qualify for high school, right? Did you study enough at school? Oh—and I left some extra textbooks on your desk. I’m sure they’ll help!”
She turned back around, her eyes bright with an eagerness Mafuyu could never quite understand. Mafuyu forced a gentle smile—because that was all she ever seemed able to do with her mother. Smile. Study. Repeat.
“Thank you, Mom. I’ll take a look at them now,” she said softly.
She shrugged off her jacket and hung it up, but the moment it left her body, the warmth of the living room vanished. A cold thinness spread across her arms and shoulders, making her shiver. The heat from moments earlier felt like a memory someone else had lived.
Quietly, she slipped into her bedroom and closed the door with a careful click. The second she was alone, a sharp breath tore out of her, almost like she’d been holding it since she walked through the front door. Mafuyu slid down to the floor, the wooden boards cool beneath her palms as she crawled toward the heat pump. With trembling fingers, she turned it up to the highest setting.
The machine hummed to life, releasing waves of soft warmth that wrapped around her back. She leaned into it, letting the heat sink into her skin. Her hands drifted over the vent, hovering just close enough for the warmth to redden her fingers. Only then did her shaking begin to settle.
After a long moment—maybe minutes, maybe more—Mafuyu pushed herself back to her feet. The warmth slipped away as soon as she stepped forward, replaced by the same thin cold that crept under her skin. She approached her desk, her eyes moving over the textbooks scattered across it like clutter she didn’t remember creating. A quiet sigh slipped out.
She sat down. The chair pressed rigidly against her back, unforgiving. She hated the way it felt—always had—but she didn’t move. Instead, she lowered her head onto her arms on the desk, turning slightly so she could reach for her headphones. She placed one earbud in, her other hand groping for her phone.
She opened her music app.
Her brows furrowed almost instantly.
There was a new track on her playlist. Untitled. She didn’t remember adding anything today. Or yesterday. Or… ever.
That was strange.
Her fingertip hovered over the play button, hesitation prickling beneath her skin. Finally, she pressed it.
The screen burst into a blinding white light.
Mafuyu flinched, squeezing her eyes shut as sharp white stars flooded her vision. The room around her warped. The edges of her desk dissolved. Her breath caught.
What… What was happening?
---
“Hey Tsukasa,
So sorry, but we won’t be home today! We got a call earlier from the hospital—your sister has a fever, so we’ll stay with her for a bit and then head back to work. But you’re our best big brother, so you’ll be okay, right?
There’s dinner in the fridge. Again—we’re really sorry!
With love,
Mom and Dad”
Tsukasa stood at the counter, the note held delicately between his fingers, his school bag still weighing down his shoulders. He read the message once, twice—then again. His eyes lingered on every curve of his mother’s handwriting: the way her a always looked more like a u, the tiny flicks she added to the ends of words as if she couldn’t bring herself to stop writing.
He swallowed hard and set the note down, forcing his stiff fingers to release it. Then he sighed, long and quiet, and mentally scolded himself for feeling anything at all.
This wasn’t new.
He was in middle school now.
He’d been home alone countless times.
So why did it still sting? Why did that heavy, suffocating pressure cling to his chest, refusing to ease no matter how many times he told himself it was fine? His parents were with his sister—their sick little girl who never seemed to get better. Of course they had to be there. It made sense.
So why did it feel like the house was already swallowing him whole?
Tsukasa dropped his backpack by the front door without looking back. He didn’t bother glancing at the fridge either—even though there was a carefully cooked meal waiting inside his mom had cooked for him. He could heat it up and pretend it was fresh, pretend he wasn’t eating completely alone in a giant, silent house.
But the thought made him feel even emptier.
It didn’t matter. He’d had a sandwich at school anyway. That was enough. More than enough.
He ignored the faint growl of his stomach and trudged toward his room.
The door clicked shut behind him with a soft thud. His bed looked inviting—too inviting. The blankets were warm and plush, the kind that could swallow him whole if he lay down for even a second. Tsukasa brushed his hand across the sheets absentmindedly before reaching toward his nightstand where his phone rested.
Some music, it filled in the silence..
He opened his music app, thumb hovering over his usual playlist—when something unfamiliar caught his eye.
“…Untitled?” he whispered. His voice sounded strangely distant, like it didn’t belong to him.
He stared at the track for a long moment. He didn’t remember adding anything. He didn’t remember downloading anything. But curiosity crept in anyway.
He tapped the song.
His phone lit up instantly—far brighter than it should have—flooding his room with blinding, white-rainbow light. The air itself seemed to vibrate as squares of shimmering color exploded across his vision, swirling and expanding until the room around him disappeared entirely.
And then—
Everything was swallowed by the light.
Mafuyu sucked in a sharp breath, stumbling as her feet touched solid ground—or something like it. Her room was gone. Completely gone. Instead, she stood somewhere that looked like a forest… but not a real one.
The air was neither warm nor cold. Just empty.
The trees stretched unnaturally tall, their leaves hardly moving despite the stillness. A pale, glassy lake reflected a sky with no stars. Off in the distance sat a massive house—too large to be called a house, too crooked to be called a building. And further beyond that… a rusting rollercoaster track snapped in half, like a memory someone had tried to erase.
This was confusing.
Before she could gather her thoughts, something flickered at the edge of her vision.
A boy materialized out of thin air—just like she must have. His phone clattered into his hand as he caught himself, looking equally confused and terrified. His blonde hair, fading into bright red at the tips, stuck out messily as he spun around taking in the strange landscape.
Then his eyes landed on her.
They stared at each other longer than either intended—both frozen, both unsure who should speak first.
So Mafuyu did.
“…Do you know where we are?”
The boy tensed, suspicion flickering across his face before he scratched the back of his neck, expression tight and uncomfortable.
“Uhm… no? Do you have any ide—”
A voice cut through the silence—flat, mechanical, and distinctly female.
Both teens jumped as a figure formed in front of them, glowing softly at first before sharpening into shape.
Hatsune Miku.
Except… not the Miku they knew.
Her silhouette glitched at the edges. Cat ears perched crookedly atop her head. Her pigtails were long but unkempt, strands turning grey like something draining the color from them. The turquoise only lingered faintly at her roots.
Both Mafuyu and the boy stared with wide eyes.
“H–Hatsune Miku?! Wh–what—where are we?!” the boy stammered, rubbing his eyes harshly, then pinching his cheek as if he expected to wake up.
The distorted Miku stared at them, unblinking.
“Mafuyu. Tsukasa. This is your SEKAI.”
Mafuyu blinked. Tsukasa? So that was his name.
But her attention snapped back to Miku.
“…What’s a SEKAI?” she murmured. “I got here by listening to a song called Untitled…”
Tsukasa turned toward her at this, panic flickering again—likely realizing he’d arrived the same way.
Miku nodded slowly, the movement slightly mechanical.
“This world was created from both of your true emotions. Physically shaped by what lies inside your hearts. It exists to help you understand your feelings.”
Mafuyu went still.
Her feelings?
She hadn’t felt anything real in… she didn’t even know how long. How could a place like this come from something she could barely access? And why was it combined with this boy’s? He looked like the kind of student teachers praised and forgot—average, normal, hardly someone whose emotions could build a forest.
Tsukasa paled.
“Wait—wait, wait—what? TRUE feelings? This—this is a forest! How do you feel a forest?!” He pressed a hand to his forehead. “And, uh—Miku, what are you even doing here? How are you real right now?”
A reasonable question, Mafuyu thought, nodding faintly as she studied Miku’s uncanny appearance.
“I am a virtual singer born from your emotions as well,” Miku replied evenly. “Just like this SEKAI.”
That… somehow made a sliver of sense. Mafuyu exhaled shakily and spoke again.
“What does this have to do with Untitled? Did it bring us here? And… how do we get back?”
“It did,” Miku said. “You can enter and leave this SEKAI through Untitled. It is an unfinished song. When you come to understand your true feelings, it will gain a melody… and a name.”
Mafuyu quickly grabbed her phone.
Untitled was still playing—its progress bar frozen yet moving, both at once.
None of this made sense.
Not the forest.
Not Miku.
Not the stranger beside her.
Not the idea that any of this came from her heart.
She stared at the blinding white track still glowing on her screen, her breath uneven.
This was impossible.
And yet… she couldn’t deny she was standing in it.