The demon lord is my girlfriend

The Crimson Morning

The Underworld's sky was a wound that refused to heal, a jagged tapestry of crimson and black that stretched endlessly above. It was as though the heavens themselves bled, their veins torn open by some ancient, unspoken calamity. The light that filtered through was unnatural—a dim, pulsing glow from an unseen sun that hung low on the horizon, like a dying ember clinging to its last breath. Shadows stretched long and thin, their edges blurred as if they were alive, creeping across the cracked earth with a slow, deliberate intent.

The air was thick, heavy with more than just heat. It carried a weight, an oppressive force that pressed against Naomi's skin, making each breath feel labored, each thought sluggish, as if the very atmosphere conspired to slow him down. The scent of sulfur and ash lingered, mingling with something darker, something metallic—like the tang of blood left to dry in the sun.

Inside Koka's home, the flickering candlelight struggled against the encroaching darkness. The flames cast uneven shapes across the wooden walls, their dance creating shadows that seemed to shift when unobserved. The house itself was a labyrinth of clutter—shelves overflowing with ancient tomes, jars filled with unidentifiable substances, and trinkets that hummed faintly with residual magic. The air smelled of incense, aged parchment, and that faint metallic undertone that Naomi couldn't quite place. Beneath the floorboards, a low, almost imperceptible hum of magic thrummed, like the heartbeat of the house itself.

Naomi sat slumped in an old wooden chair, his silver eyes dull and distant. His fingers traced the grooves of the worn table in front of him, the rough texture a feeble attempt to anchor him to reality. The table was scarred with countless marks—etchings, burns, and stains that told stories of their own. His mind wandered, drifting back to the events that had brought him here. Aiko's face flashed in his thoughts, her scarlet eyes filled with determination as she stepped through the portal, leaving him behind.

It had been a week. A week of waiting. A week of uselessness.

His stomach twisted with frustration, a gnawing ache that refused to subside. Every moment that passed felt like sand slipping through his fingers, each grain a reminder of his helplessness. Aiko was out there, somewhere in this twisted world, and he was stuck here—trapped in a house that felt more like a cage with every passing hour.

The thoughts churned inside him, building until they had nowhere to go. His hand clenched into a fist, and before he realized what he was doing—

THUD.

Pain shot through his palm as his fist met the table. The impact sent a sharp ache up his arm, jolting him back to reality. The sound echoed in the quiet room, startling him as much as the pain did.

"Ow! Stupid, stupid—why did I do that?"

He exhaled sharply, shaking out his hand. The dull throbbing was nothing compared to the frustration gnawing at him. His gaze drifted, landing on something strange resting atop the table.

A hat.

It was wide-brimmed, lined with intricate silver embroidery that shimmered faintly in the dim candlelight. The patterns were delicate, almost alive, shifting ever so slightly as if they were breathing. The hat seemed out of place amidst the clutter, too pristine, too deliberate.

Naomi frowned. That hat… where have I seen it before?

The thought tugged at the back of his mind, just out of reach. A game? An anime? A dream?

His fingers hesitated before brushing against the fabric. It was cool to the touch, unnaturally smooth, almost like silk woven from shadows. The moment his skin made contact, a faint hum resonated through his fingertips, a whisper of magic that sent a shiver down his spine.

A voice cut through the silence, snapping him from his thoughts.

"Hey, kid."

Naomi flinched, looking up sharply.

Koka stood in the doorway, leaning on her gnarled staff. Her piercing blue eyes studied him with an unreadable expression, the candlelight making the deep lines on her face more pronounced. Her presence was like a storm contained within a single person—calm on the surface but brimming with unspoken power beneath. Her cloak, a patchwork of dark fabrics, seemed to absorb the light around her, making her appear almost spectral.

---

A Meal and a Warning

Koka moved with slow precision, setting a plate of scrambled eggs on the table. Steam curled into the air in thin wisps, carrying a scent that was painfully familiar.

Naomi's stomach growled in response.

"Eggs? They have eggs here?"

Koka smirked, settling into a chair across from him with her own plate.

"Not everything in the Underworld is strange. Some things are… similar to your world. Eggs, for example. Though I wouldn't ask where they come from."

Naomi hesitated, fork halfway to his mouth.

"You can't just say something like that!"

Koka chuckled, a low, raspy sound that carried a hint of warmth. But her eyes remained sharp, always watching, always calculating.

Naomi sighed, finally taking a bite. The taste was shockingly normal—warm, slightly salty, just like home. A wave of nostalgia hit him, uninvited and unwelcome. For a brief second, he was back in his small apartment in Tokyo, eating a rushed breakfast before school. The memory was so vivid he could almost hear the hum of the refrigerator, the distant sound of traffic outside.

His grip tightened around the fork.

"Thanks, Koka. For… everything."

She nodded, though her gaze remained sharp.

"Don't get too comfortable. This isn't a vacation."

The warmth in Naomi's chest chilled instantly. His appetite vanished.

"Yeah. I know."

Koka finished her meal and stood, brushing crumbs from her cloak.

"I'm heading out. Stay here, and don't even think about stepping outside."

Naomi groaned, slumping in his chair.

"You really don't trust me, huh?"

Koka adjusted the hat on her head with practiced ease, her smirk returning.

"No, I don't. And for good reason."

She turned to the door, but Naomi's thoughts raced ahead of him.

"Where is she going? Maybe I could follow—"

Koka paused mid-step, glancing over her shoulder.

"I heard that."

Naomi stiffened.

"Were you listening to my thoughts?!"

Koka smirked.

"It's my house. I do what I want."

He groaned, running a hand through his messy hair.

"Fine. I'll stay put."

Koka's expression softened—just a little.

"I know you're restless. But it's dangerous out there. Trust me. When I get back, I'll help you figure things out."

Naomi looked up at her, frustration clashing with gratitude.

"Thanks, Koka."

She gave him a final nod before stepping outside. The wooden door shut behind her with a soft click, leaving Naomi alone in the heavy silence of the house.

---

The Uninvited Guest

Naomi exhaled slowly, turning toward the door. His fingers hovered near the handle.

"A single wooden door is all that's keeping demons from storming in. Comforting."

The house creaked faintly, settling into silence.

Then—

"You wouldn't have any trouble if you weren't alone."

Naomi's heart stopped.

The voice was soft, melodic—too casual, too smooth. He turned slowly.

A boy sat on the table, legs crossed, golden eyes glowing faintly in the dim light. He looked no older than twelve, his hair the color of sunlight, his small hands resting idly on his lap. A gentle smile played on his lips.

Something about him was wrong.

"Who… who are you?"

The boy tilted his head slightly, his golden gaze unblinking.

"My name's Taros. You must be one of Koka's students."

Naomi's blood ran cold.

"What?"

Taros chuckled—a sound light and airy, yet somehow suffocating.

"What's your name?"

"Naomi."

Taros's golden eyes gleamed with something unreadable.

"Big brother Naomi."

A chill ran down Naomi's spine.

The air in the room felt heavier, thick with an unspoken presence.

"Who is this kid? And why does he feel so… wrong?"

Taros leaned forward slightly, his hands resting on the wooden surface. The candlelight cast deep shadows across his youthful face, making him look both childlike and ancient all at once.

"So, where's Koka?"

Naomi hesitated.

"She went out."

"Did she tell you where?"

Naomi shook his head.

"No."

Taros hummed thoughtfully, as if Naomi had just told him something interesting. Then, with that same unsettling smile, he swung his legs off the table and stood, his movements unnervingly smooth.

"Big brother Naomi, do you want to go out with me?"

A pit formed in Naomi's stomach. He didn't know why, but everything inside him screamed to stay put.

"No. I have to stay here."

Taros's golden eyes darkened, but only for a fraction of a second.

"Why?"

"Because Koka told me to."

The moment the words left Naomi's lips, the air in the room shifted. It wasn't dramatic—no sudden gust of wind, no flickering lights—but something unseen, something heavy, pressed down on the space between them.

Taros's expression barely changed, but Naomi felt it.

A moment stretched between them, silent and suffocating.

Then, Taros took a slow step forward.

"Do you really know who Koka is?"

Naomi swallowed hard. He couldn't answer.

"Is he really just a kid? Or something else?"

Taros took another step, closing the space between them. His golden eyes bore into Naomi's, and for a fleeting moment, Naomi swore he saw something inside them—something vast, something ancient.

"Big brother, are you okay?"

Naomi forced a smile, though his fingers dug into his palms beneath the table.

"Yeah. I'm fine."

Taros studied him a moment longer, then his smile returned—pleasant, polite, unreadable.

"I have to go now. But remember, you won't achieve anything in this world if you don't try. You have to be brave and strong to do what you want."

Naomi barely had time to process the words before Taros turned, walking toward the door.

The wooden door creaked as he pushed it open. The crimson glow of the Underworld seeped inside, staining the room in deep, unnatural hues.

Naomi's mind raced.

"Wait… how did he even get in here?"

The door clicked shut behind Taros, leaving Naomi in silence once more.

He sat there, unmoving, staring at the door. The weight of Taros's presence still lingered, an invisible residue that made the air feel thick.

His hand hovered over the handle.

"Everything will change if I open this door…"

---

The Chess Analogy

Outside, Taros paused beneath the red sky. His figure stood motionless in the glowing haze, but Naomi swore he felt those golden eyes on him through the door.

Then, without turning, Taros spoke.

"Do you play chess, big brother Naomi?"

Naomi blinked.

"Chess?"

"Uh… a little, I guess."

Taros smiled, his voice carrying a strange amusement.

"The king is the most important piece. But he's also the weakest. He can't do much on his own. He needs his soldiers, his knights, his rooks… but what happens when the king loses all his soldiers?"

Naomi frowned, his mind struggling to keep up.

"I… I guess he loses the game."

Taros's smile widened.

"Exactly. A king without his army is just a piece waiting to be captured. Remember that, big brother."

With that, Taros turned and walked away, disappearing into the red mist.

Naomi remained frozen, his fingers still hovering over the door handle.

His mind swirled with questions, with unease.

"What was that about? Was he warning me? Threatening me?"

He exhaled slowly, forcing himself to take a step back. The weight of Taros's words clung to him, heavy and unsettling.

"A king without an army…"

For the first time in days, he felt a strange clarity.

He couldn't stay here.

His hand clenched into a fist.

"I have to choose. Everything will change if I open this door."

---

Meanwhile, at the Demon King's Castle…

The grand corridors of the Demon King's castle stretched endlessly, their obsidian walls adorned with intricate carvings that seemed to shift when unobserved. The air was thick with the scent of burning incense and something deeper—something ancient, something laced with power.

Koka walked with purpose, her staff tapping against the polished stone floor. Her eyes remained ahead, though her mind was elsewhere.

She reached the towering doors of the throne room. Without hesitation, she pushed them open.

Inside, the vast chamber loomed, its ceiling disappearing into shadows. Enormous obsidian pillars lined the room, glowing faintly with golden inlays that pulsed like slow-moving veins. At the far end, atop a raised dais, sat the throne—black, jagged, and impossibly large.

Beside the throne, Aiko stood, her scarlet eyes locked onto Koka as she entered.

And sitting on the throne itself—Taros.

The boy lounged casually, one leg draped over the armrest, his golden eyes gleaming with amusement.

Aiko's voice rang through the chamber, sharp and formal.

"Koka, the strongest witch and one of the four legendary magic users of Blastos Kingdom."

Taros chuckled softly.

"You don't need to introduce her, Aiko. That's not your job."

Koka gave a slight bow, though her face remained unreadable.

"My king, I would love to know the reason for summoning me."

Taros's smile faded, his golden gaze narrowing.

"Don't pretend to respect me like this. I hate liars."

A flicker of something passed through Koka's eyes, but she remained still.

Her grip tightened on her staff.

"I'm sorry."

Taros's smirk returned, but colder this time.

"So, tell me, Koka…"

The tension in the room thickened. Aiko's gaze flickered between them, unreadable.

Koka's heartbeat quickened.

"Does he know about Naomi?"

Taros leaned forward, resting his chin on his hand.

His voice was light, almost playful.

"Who is the traitor?"