After crossing the boundary between worlds, Kaiba finally reaches Atem again.
Their reunion is everything it should be: a duel, a kiss, and a night spent together after far too long apart.
Then Kaiba discovers that, in ancient Egypt, underwear was apparently not a thing.
Atem sees absolutely no problem with this.
Kaiba disagrees.
This is a translation of an original work on Pixiv.
Original Title: パンツという文明 前日譚
Original Author: 葉人(@Hathor₋yuki)
Personal site: https://prideshipping.sakura.ne.jp
The sky of the Underworld was a slightly deeper blue than that of the living world.
The clouds did not drift; only the wind existed.
With that wind at his back, Seto Kaiba stood.
This was the world of ancient Egypt.
Golden pillars and floors of white stone—all of it was silent.
And at its center was Atem.
“…You’re late.”
Atem was the first to speak.
He stood before the throne, arms crossed, cloaked in his usual kingly dignity.
But the corner of his mouth was faintly softened.
Kaiba snorted.
“Who was the one who disappeared without a word?”
“Yet here you are.”
“Yeah.”
It was a short exchange.
But it was enough.
Though there should have been distance between them, they were already within each other’s breathing space.
Their reunion was not dramatic. There were no shouts, no hesitation.
Simply being here was enough.
“…I knew you would come.”
Atem added quietly.
His voice was no longer that of a king—it was the voice only Kaiba knew.
Kaiba shrugged.
“Of course.”
Atem’s eyes softened, narrowing gently.
“…Yeah.”
He said nothing more.
If he did, something inside him might overflow.
Instead, Kaiba raised his left arm.
A Duel Disk.
Atem mirrored him, taking the same stance.
“Let’s start with this.”
“Heh… Of course it comes to this.”
Atem’s smile deepened.
“A greeting for our reunion.”
The duel did not last long.
They knew each other completely—
their thoughts, their habits, even the way those habits had changed.
And yet—
No, precisely because of that—
Every single move was enjoyable.
The victor was decided, but the loser’s face held no trace of defeat.
It was the face of a lover.
Silence returned.
Only their breathing remained.
Then, as if by mutual agreement, they walked toward each other.
The distance vanished.
“…You really came,” Atem whispered.
Kaiba gave no answer.
Instead, he reached out and touched Atem’s cheek.
It was warm. He was really there. Not an illusion.
Atem closed his eyes and leaned into that hand.
“You thought I wouldn’t?”
That was all he said.
Atem smiled faintly.
“…No.”
Naturally, their shoulders touched.
Their breaths mingled.
Neither could say who moved first.
Their lips simply met.
It had been a long time, yet nothing had changed.
If anything, the kiss was deeper than before.
“…Kaiba.”
“Atem.”
Just calling each other’s names loosened their restraint.
Atem’s fingers clutched Kaiba’s coat, as if he would never let go.
Kaiba pulled Atem’s body closer.
“Let’s go to the room.”
It was neither a command nor a suggestion. It was simply a fact.
Atem nodded. There was no reason to refuse.
No—he had been longing for it.
The Pharaoh’s private chamber.
A white bed. Golden decorations. A quiet space.
The moment the door closed, their lips met again.
This time, more intensely than before.
Atem’s back touched the bed. Their bodies sank into it together.
The white linen wrinkled beneath them.
Their breaths were close. Too close.
“…It’s been a while,” Atem said with a faint smile.
“…Yeah.”
Kaiba’s hand slid around Atem’s waist—
holding him tightly, as if he would never lose him again.
As if to fill the empty space between them.
With a completely relaxed, trusting expression, Atem closed his eyes.
And so, the two of them once again found their way to the bed together.
The royal palace of the Underworld was wrapped in a faint twilight, where golden decorations glowed softly.
The white linen gently embraced the chill of the night.
Kaiba pulled Atem’s slender waist close, wrapping his arms around his back.
Hot breaths brushed against each other’s lips.
Their kiss was deep and ravenous. The only sound breaking the silence was the wet noise of their tongues intertwining.
“Nn… Kaiba…”
Atem’s voice was slightly hoarse as he called his name.
As if guided by that sound, Kaiba’s hand slowly traced the line of Atem’s waist—over the shenti, and then beneath it.
But the sensation he expected was not there.
His fingertips touched hot, smooth bare skin directly.
There was nothing in the way.
Kaiba’s movements stopped abruptly.
“…Atem. You…”
His voice grew lower, hoarse enough that he himself noticed it.
His blue eyes blinked once in surprise, brows furrowing.
His fingertips stroked the base of Atem’s inner thigh once more, as if to confirm.
The result was the same.
Nothing.
No covering.
No barrier.
Only heat.
Soft pubic hair and Atem’s already half-hard length pressed directly against his palm.
Atem, still dazed from the kiss, narrowed his eyes and looked up at Kaiba’s face.
“What’s wrong…? It tickles.”
He tilted his head slightly, his voice purely curious.
There was no shame, no wariness. Just an innocent question.
For a moment, Kaiba couldn’t answer.
A faint heat rose in the back of his throat.
The ancient Pharaoh had no way of knowing modern common sense.
“…You’re not wearing anything.”
His fingers slid deeper, gently wrapping around the hot tip.
Atem’s hips jerked sharply.
“Hah…!? Under the shenti? Why?”
The question was completely natural. There wasn’t a trace of embarrassment in it.
“Because this is my Underworld.”
It was simply a difference in common sense.
That was all.
Or at least, it should have been.
Kaiba exhaled.
An innocent smile appeared on Atem’s face.
That smile burned Kaiba’s reason even more.
“…You really are…”
Kaiba growled lowly and pushed Atem down onto the bed.
He hiked up the shenti and spread those slender thighs wide.
“…Is this really okay with you?”
The whisper was as much for himself as it was for Atem.
His fingers moved slowly.
Touching.
Confirming.
Every time, Atem’s breathing trembled.
“…Ah.”
This time without hesitation, Kaiba firmly grasped Atem’s length and began stroking it up and down.
“Nn… ah… Kaiba…!”
Atem’s voice melted into sweetness.
Kaiba brought his lips to Atem’s ear and breathed hotly against it.
“Good. Today, I’m going to thoroughly dye you with my common sense.”
His fingers moved faster.
Atem’s hips rocked lewdly, and sweet moans echoed through the royal palace of the Underworld.
The hiked-up shenti was now nothing more than a decoration.
The body heat of the two men intertwined, and in the space between ancient and modern, a scorching, melting night began.
Kaiba’s hand gripped Atem’s heated length tightly and stroked it up and down without mercy.
Although surprise had certainly burned in his chest, Kaiba’s reason still remained coldly intact.
Yet deep beneath that cold rationality, a beast-like urge was also swelling.
“Hah… ah…! Kaiba, wait… it’s too intense…”
Atem gasped, clutching Kaiba’s shoulder with slender fingers.
He looked up with eyes mixed with confusion and pleasure, brows furrowed.
The ancient Pharaoh still couldn’t understand why the fact that he wore nothing beneath his shenti was driving Kaiba so wild.
He simply thought that Kaiba was a little rougher tonight because it had been so long since they last touched.
“Nn… Is it because it’s been so long…? Kaiba… were you waiting for me…?”
Whispering in a sweet, hoarse voice, Atem rolled his hips himself, rubbing against Kaiba’s hand.
That innocent reaction scraped away at Kaiba’s reason even more.
“…It’s because you’re far too defenseless…”
Kaiba growled low in his throat and sped up the movement of his fingers.
While his thumb rubbed roughly against the sensitive tip, his other hand pinched Atem’s nipple.
Their kiss was deep—teeth grazing lips, tongue invading all the way to the back of his throat.
It was so fierce it stole even Atem’s breath, pressing his body deep into the bed.
“Nh…! Ah, aah…!”
Atem’s back arched involuntarily.
His slender throat was exposed as sweet cries spilled out.
He still believed that Kaiba was only this intense because it had been a long time.
The shenti was already bunched up around his waist, reduced to a meaningless scrap of cloth. Kaiba hooked Atem’s legs around his own waist and pressed his own hardened length directly against the hot crevice between Atem’s thighs.
Just that pressure made Atem tremble violently.
“…Atem. Today, I’m going to teach you just how defenseless you are.”
His reason was still holding on.
Yet that very reason was driving Kaiba to act even more fiercely.
His fingers explored Atem’s inside, gently—no, not gently at all—loosening the tight entrance.
Atem simply moaned sweetly and wrapped his arms around Kaiba’s neck.
“Kaiba… more… come inside me…”
Without understanding anything, the Pharaoh willingly surrendered his body to the beast.
The bed in the Underworld grew hot to its very core with their body heat and the wet sounds of their passion.
The night had only just begun.
Kaiba’s fingers mercilessly stirred inside Atem’s tight entrance.
The shenti had been completely pushed up to his waist, now nothing more than ornamental fabric.
The fact that Atem wore nothing underneath was an unbearably sweet trap for Kaiba.
“Nh… hah, ah…! Kaiba, your fingers… they’re so deep…!”
Every time Atem’s hips bucked, the hot, wet inner walls clenched tightly around his fingers.
There was nothing to block him.
Even when he added a second and then a third finger, they sank all the way to the base with ease.
Kaiba deliberately made wet, obscene sounds as he stirred them, as if to confirm it.
“Nothing… Is this how you always are…?”
He whispered in a low, husky voice while simultaneously stroking Atem’s front with his thumb.
His reason still held, but that very reason only accelerated the urge to take everything right now.
Atem shook his head with teary eyes.
“Nn… What do you mean… always…?”
His breathing was ragged, golden hair spread across the sheets.
“It’s just… because it’s been so long… you’re only this… intense, right…?”
Those innocent words inflamed Kaiba even further.
Kaiba laughed shortly and pulled his fingers out.
In their place, he pressed his own throbbing, rock-hard length directly against Atem’s entrance.
The tip slid in slickly, burying halfway without resistance.
“Hah…! Ah, aah… nn! Wait, not so suddenly…!”
Claws dug into Kaiba’s shoulders.
Kaiba thrust his hips forward in one powerful motion.
He sank all the way to the root.
There was no underwear fabric, no elastic band—nothing.
Just hot flesh meeting hot flesh directly.
“Atem… This is your fault… Accepting me so easily like this…”
Kaiba’s movements grew even more violent.
He slammed his hips with enough force to make the bed creak, driving into the deepest part every time.
With one hand he pushed Atem’s leg up high, and with the other he stroked him hard.
Obscene, wet sounds filled the air.
The lewd, wet schlick-schlick of flesh slapping against flesh filled the silent Underworld.
“Nn, ah, aah…! Kaiba…! It’s… too much…!”
Atem could only moan helplessly.
He never dreamed that the fact he wore nothing underneath was driving Kaiba this crazy.
He simply believed Kaiba couldn’t hold back because of their long-awaited reunion.
That lack of awareness made Kaiba even more ferocious.
Kaiba captured Atem’s lips, tangling their tongues deeply while continuing to pound into him.
Sweat mingled as their bodies pressed completely together.
The shenti had been kicked all the way to the edge of the bed.
“…Atem. It’s because you’re too defenseless… And you can’t stop me either, can you…?”
Kaiba’s reason was beginning to melt in the heat.
So was Atem’s.
Atem simply cried out sweetly, arms wrapped tightly around Kaiba’s back, continuing to accept the beast’s love.
The royal palace of the Underworld was melted to its depths by their fierce heat.
The night was still long—
The heat that had melted them together just moments ago had already changed form, spreading across the bed as a soft, lingering afterglow.
Though the air in the Underworld’s night was supposed to be cold, only the space beneath the linen remained faintly warm.
Atem rested his cheek against Kaiba’s chest and let out a shallow breath.
“…Kaiba.”
He spoke his name, but no further words followed.
Simply saying it was enough for a deep sense of fulfillment to bloom inside his chest.
He could feel Kaiba’s arm still wrapped around his back.
It wasn’t just an embrace — it felt more like Kaiba was holding him there to confirm he was real, refusing to let him go.
“What is it?”
A low voice fell onto his hair.
“…Nothing.”
Atem smiled softly.
“Maybe it’s because it’s been so long… You were a bit… intense tonight.”
It was an honest thought.
Compared to the times they had shared in the living world, Kaiba had been more forceful, deeper, and far less merciful.
Yet it hadn’t been unpleasant.
His body still remembered the undeniable heat hidden beneath that ferocity.
“…I see.”
Kaiba’s reply was short.
But the arm around him tightened just slightly.
Atem closed his eyes.
Pressing his ear to Kaiba’s chest, he could hear a steady heartbeat.
This man was here.
That alone was enough.
They had finally embraced after so long.
That was enough.
He was satisfied.
All without knowing.
Without noticing anything.
Kaiba ran his fingers through Atem’s hair.
The fine, silky strands felt pleasant as they tangled around his fingertips.
He was satisfied.
Certainly.
The warmth in his arms. The voice that called his name.
Everything was there, tangible and real — something he had obtained.
But at the same time, another sensation refused to leave him.
His fingertips still remembered.
The feeling of that moment — when there had been nothing separating them.
The heat he had touched directly.
Kaiba narrowed his eyes slightly.
In his arms, Atem wore a peaceful expression.
Completely defenseless.
Without a single doubt.
As if it were the most natural thing in the world.
His face showed no question at all about the fact that he wore nothing underneath.
“……”
His gaze unconsciously drifted downward.
The shenti had been neatly fixed back into place.
But Kaiba now knew what lay beneath it.
He had learned the truth.
That this was now “normal” for Atem as Pharaoh.
His fingers unconsciously stroked Atem’s back.
Atem snuggled closer in response — a reaction full of complete trust.
That innocence left a strange feeling in the depths of Kaiba’s chest.
Did he want to protect him?
To corrupt him?
To reshape him?
It was an urge he couldn’t yet name.
“Kaiba…”
Atem murmured, already half-asleep.
“…What?”
“Are you… still here…?”
It was a voice both spoiled and seeking reassurance.
Kaiba exhaled softly.
“I’m here.”
At that short answer, all the tension left Atem’s body.
He had fallen completely asleep.
Kaiba looked down at his sleeping face.
He was satisfied.
He truly was.
And yet, at the same time, his thoughts had already begun turning toward the next step.
— Could he really leave this man as he was?
No. He had no intention of leaving him like this.
Kaiba quietly closed his eyes.
Feeling the warmth in his arms,
in the midst of the sweet afterglow, he unconsciously began planning a new “introduction.”
Author's Note:
Kaiba is not the only one who had a cultural crisis while researching this topic.
Modern-style underwear is surprisingly recent. Garments resembling modern underpants began to appear around the 16th century.
In other words, this entire fic may have been inevitable.
