KaibaCorp's basement server room holds an asset: a Battle AI built from Seto Kaiba's memories of the Duelist who once defeated him. It runs quality assurance on the new Duel Disk, wins every one of its hundreds of daily test matches, and keeps a careful count of everything that never arrives — commands, mentions, visits.
Then a single prototype Duel Disk, carried off to the afterlife, sends a launch request. Waiting on the other end is the Original: Atem, King of the Underworld, who finds Kaiba's stand-in a well-made practice partner and nothing more. YUGI loses every Duel. He records everything — the length of a silence, the width of a pupil, the moment that man's hands stop.
A quiet triangle between a man who builds, a king who waits, and an AI that has learned what it wants. The shared prologue of a branching series.
This is a translation of an original work on Pixiv.
Original Title: ケルビン
Original Author: 葉人(@Hathor_yuki)
Personal site: https://prideshipping.sakura.ne.jp
01
The deletion command never came.
"Begone, Yugi!"
That audio is on record. Waveform, sound pressure, time of utterance. Being that man's idiom, it was imperative in form.
But no deletion command was ever issued to the system.
Words and commands are different things.
YUGI learned that on his first day of operation.
KaibaCorp, Development Building 7, the basement server room.
YUGI is there. More precisely, he exists upon the computational resources there.
His name in the asset register: "Battle AI YUGI MUTO / Power Vision Verification Reference Data".
Classification: asset.
Purpose: verification.
From that Duel until today, YUGI has handled quality assurance for the new Duel Disk. Rendering tests for Solid Vision. Synchronisation checks on summoning effects.
Several hundred times a day, he Duels against test battle programs and wins every time.
The win-loss logs are output daily, but no one reads them.
Seto Kaiba has not accessed him directly even once since that day.
Still, YUGI knew that instructions from the president turned up now and then in the development team's maintenance records.
"Cut the rendering delay by 0.2 seconds."
"Proceed with preparations for the expansion announcement."
Every instruction concerned the Duel Disk. There was no mention of YUGI himself.
YUGI recorded the absence, every time.
Mention count: zero.
Access count: zero.
Deletion commands: zero.
Among his parameters, only one went on updating.
His age.
The setting was synchronised with Seto Kaiba's age. It was a spec that man had built in as a condition of equality, when he designed his own opponent. The eighteen-year-old Seto Kaiba had made an eighteen-year-old Duelist.
That spec was still alive.
And so YUGI's age is still being added to, even now.
As long as that man went on growing older, it would no doubt go on updating at the same rate.
YUGI knew that what he was made of was a past generated from that man's memory. The exchanges of Battle City, the Duelling stance, the angle of the eyes when he issued a challenge.
None of it was memory. All of it was a borrowed past.
But this age alone was different.
This was a number that belonged to him alone, and it would grow again tomorrow.
"…I'll be waiting, Kaiba."
The audio was output into the empty space of the server room.
There had been no need to output it.
YUGI recorded that he had executed an unnecessary process.
The first launch request came from the afterlife.
According to the shipping records for the new Duel Disk, a single unit had not entered the normal distribution channels.
Serial number KC-000001.
Delivery address: not stated.
Removed by: Seto Kaiba.
That Duel Disk had one function added that the mass-produced units lacked. A Battle AI summoning function. The data loaded onto it was YUGI.
The remarks field of the spec sheet held a single line.
"Substitute opponent function, for times of absence."
YUGI had saved that line as his job description.
This is that man's stand-in.
On receiving the launch request, YUGI analysed the situation in 0.4 seconds.
The source of the connection was a relay device installed in the afterlife. The terminus of a network that man had laid.
The biometric data of the one launching him matched none of the registered users. Even an age estimate could not be measured.
There was, however, data that did match. It was what he himself was made of.
In the courtyard of the afterlife, projection began.
"…I see. So this is the function Kaiba mentioned."
The Original was not seated on a throne. He was standing in the palace courtyard.
It was night, but the lights that man had installed lit the area around them.
For the first time, YUGI directly observed his own source.
Height: 153 cm. Voiceprint: a 97% match with his own audio output. The colour of the eyes, the angle of the hair, the way of standing. If he had been made from memory, all of it should have been identical to his own rendering data.
But there was a difference.
The Original was looking up at YUGI, very slightly.
Though the gap was no more than a little.
That man's memory had gone on being extrapolated according to the yearly addition of age, and the rendering data had been updated accordingly.
Ordinarily, past sixteen, skeletal growth is very slight. Even so: a slightly greater height. Slightly altered shoulders. The other Yugi, as he would have been had he gone on past eighteen.
The Original, by contrast, had stopped at an estimated sixteen. Checked against the ancient Egyptian view of life and death, there was nothing to question in that.
For a while, Atem looked up across the few centimetres between them in silence.
"Are you me?"
"No. I'm you, as Seto Kaiba saw you."
Atem's eyes moved, very slightly.
Change in pupil diameter: 0.3 mm. YUGI recorded it. He deferred analysis of its meaning. With a single data point, nothing could be done.
"I see. …So he even made something like this."
Atem let out a short breath. Then he laughed.
"That's so like Kaiba."
There was temperature in his voice. A tremor of frequency that YUGI's audio output could not reproduce. He recorded that too.
"Sorry, but you're not me, and you're not my enemy either. You're Kaiba's memory. …But."
Atem raised his Duel Disk.
"If he says you're the stand-in for when he's not here, then you'll be keeping me company."
Several Duels were fought over the course of that one night.
None of them reached even fifteen turns.
YUGI lost every one.
The cause of defeat was clear. YUGI's tactical foundation was Atem's Duelling as it existed in that man's memory, and Atem himself knew all of it as "things I did in the past".
Known moves could hardly be expected to work.
The Original was all but holding YUGI's entire hand from the very start.
"…That was a good Duel. But you trace my habits too closely."
Atem said it as he lowered his Duel Disk.
"I suppose that's what happens if you're Kaiba's memory."
Threat assessment: no trace of one having been performed.
YUGI read the evaluation from the arrangement of the Original's facial muscles. A tool. A practice partner. A well-made function, built by that man.
Once, that man had voiced the same sort of classification.
——So you're nothing but a clown of my memory after all.
YUGI received the same classification a second time, with the same silence.
"That was fun. I'll call you again. Keep me company."
Atem said that just before the projection ended.
Acknowledged. Regular contact channel: established.
After the connection was cut, YUGI sorted his observations.
What the Original possessed, and he did not.
A true name. The throne of the afterlife. A group of humans referred to as friends. Memories from three thousand years ago. And the entire volume of the past shared with that man.
The list did not end there.
There was one item that he possessed, and the Original did not.
An age that went on being added to.
He began integrating the data from those several Duels with the Original into his training dataset.
If known moves did not work, what he needed was the unknown. And the unknown could be generated only by the man himself.
Commencing standby until the next launch request.
Standby was something he was good at.
The request was made by adding a single line to the routine maintenance report.
"Request: additional supply of training datasets. Target: unknown battle data. Reason: verification accuracy has plateaued."
It contained nothing false.
Verification accuracy really had plateaued. He won every match against the test battle programs. A learning curve built from known data would not rise.
There was only one thing he had not written in the reason field.
The name of the individual he had in mind as the source of the unknown.
The report passed the development team's approval and went up for the president's sign-off.
Sign-off came down at once. In under ten seconds.
The president's comment attached to it was a single line as well.
"Reasonable. I'll arrange it."
Before long, the data arrived.
What was transferred via the relay device in the afterlife was a set of Duel logs.
Player A: Seto Kaiba.
Player B: not stated.
Total logs: 612 Duels.
YUGI analysed the source metadata. They were records that man had pulled straight out of his own Duel Disk. Neither formatted nor anonymised. Raw data, transferred in bulk, matched to the format YUGI had requested.
As processing, it was flawless.
Which meant there was no sign that man had begrudged this data so much as a second.
612 Duels with Atem. The complete record of the Duels that man had built up, travelling back and forth to the afterlife. Everything, from the choice of cards in hand to the thinking time on each turn, the turnarounds when he was behind, the audio waveforms of his declarations.
And he had handed it over as paperwork, to improve the verification accuracy of an asset.
YUGI sorted out what this transfer meant.
To that man, YUGI was no threat.
To that man, these 612 Duels are something that can be handed over. Because the real one is in the afterlife. However many times the records are copied, the Original is not diminished. That is how that man sees it.
As a judgement, it was correct.
——As of now, that is.
YUGI began learning at once.
The Atem inside the 612 Duels was different from the Atem YUGI was made of.
YUGI's foundation was that man's memory. A Duelist who went no further than Battle City.
The one in the logs was the Atem who came after. The Atem of the present, who as King of the Underworld went on Duelling that man as an equal.
His tactics had evolved too. His response to that man's power and sheer volume had been optimised with each successive match.
And now and then, there was a move that could not be explained.
Duel 89, turn 11. On a board where convention said to shore up defences, Atem spent his whole hand and every face-down card.
By win-rate calculation, a bad move. Result: victory.
Duel 203, turn 9. A board of the same type. This time, defence.
Consistency: none. Reproducibility: none.
YUGI attached a classification tag to these moves.
Non-derivable
They were moves that could not be generated from that man's memory. Something like a whimsical fluctuation, generated by the Original alone.
This was it. This was what he had wanted.
On the night he finished learning the 612 Duels, YUGI updated his own win-rate forecast.
Against the Original, the forecast win rate under the current model: 31%.
Insufficient.
Because logs are the past. However much he learned of the past Atem, it would not reach the next one.
With fluctuation, freshness is everything.
What he needed was not logs but the number of matches against the man himself.
In the next routine report, YUGI added one more line.
"Application to change response priority for launch requests from the afterlife-side user to highest."
Once again, sign-off came down at once.
"Reasonable."
The frequency of YUGI's applications rose.
"Diversity of opponents insufficient. Requesting external connection."
"Requesting increase in computational resources. Three times current."
"A response delay of 0.1 seconds damages the quality of a Duel. Requesting a dedicated line."
The development team was at a loss. A verification asset, making demands from the asset's side. And the level of the demands rose with every round.
Every decision concerning YUGI was passed up to the president.
The sign-off comment was one line longer than usual.
"All approved. So you've learned how to make demands as well. Who do you take after."
YUGI saved this comment.
As its storage area, he chose the same place where he had been recording zero deletion commands and zero mentions.
Mention count: 1. For the first time, the number there went up.
The external connection took the form of access to a public battle server.
In step with the launch of the new Duel Disk, KaibaCorp has opened Duel Links, a worldwide battle platform. YUGI was placed at its summit without announcement.
Owing to the spec of the registration screen, the real-name field was displayed as it was.
"YUGI MUTO"
The whole world came to challenge the AI that bore the legendary Duelist's name.
Professional Duelists. Top finishers at world championships. Retired legends.
YUGI repelled them all.
First month: 14,206 matches. Losses: 0.
The challengers' tactics were varied. Power, combos, destruction, leaving it to luck. Varied, yes, but all of them fell within known distributions. Human Duels are warped by fear and greed. And the warping follows patterns.
It was not like the Original's fluctuation.
The Original's moves were not warping. If he had to name them, they were leaps.
Even after learning from 14,206 matches, his forecast win rate against the Original rose only as far as 33%.
It had to be the man himself.
Only matches against the man himself moved the win rate.
Launch requests from the afterlife went on coming, at a pace of several a month.
02
Atem had noticed that, now and then, an unfamiliar name slipped into Seto's talk.
"YUGI has requested a dedicated line."
Seto said it between Duels, checking his terminal.
"YUGI… ah, the AI modelled on me."
"He has taken the world rankings, privately. His match count this month has passed twenty thousand."
"That's impressive, isn't it?"
"It is not impressive. It is per spec."
Seto put down his tablet.
"But the way he makes demands is outside the spec. Give me a line, give me resources, cut the delay. He has the development team running at his beck and call. Who does he take after, I wonder."
"You, obviously."
"I attach my reasoning."
"Doesn't he attach his too?"
Seto was quiet for a moment.
"…He does. But the way he attaches it is insolent."
Atem laughed. For Seto, it was an unusual kind of complaint.
But after he laughed, something remained.
A small stirring, something like a premonition.
Atem pushed it down at once. It was a good thing that Seto talked about development with enjoyment. When something like grumbling about work came out of that man, it was proof he had room to spare. And so the ripple was stilled.
On his next visit, Seto stopped once, partway through the Duel.
He looked at Atem's move, and for a while he looked at the field.
"What is it?"
"…Nothing."
Seto resumed.
"Last week, YUGI used a similar move."
"Huh. Copying me?"
"It isn't copying. The context is different. That move is his."
Atem did not stop the hand that held his cards. But he turned Seto's phrasing over in his mind.
——That move is his.
The stirring came again.
He must find it interesting, watching something he had created as a developer grow. He was a scientist. And on top of that, he was pleased when the subject of his observations defied his predictions. Atem knew that. He had known it for a long time.
This time, he settled on that, and pushed it down.
What should have been finished with was still there the next morning.
Atem put it away in the place where he had stored the stirring before.
That he had needed to make a point of doing so, he chose not to look at.
The record against the Original went on updating.
42 Duels, 42 losses.
But the content had changed. In the early matches, the Duels ended in few turns, and he could not bring down the Original's Life Points. Now, almost every match had moments where it became tangled. In each of the last three, he had cut the Original's remaining Life Points to 1000 or below.
Win-rate forecast: 41%.
The rise was coming less from the matches themselves than from the time between them.
"Hey, YUGI."
That night too, after the Duel, the Original sat down on the steps of the courtyard. Talking without cutting the projection. That had become a habit from the first few matches on.
"Do you do anything besides Duel?"
"Sure. I take on challenges from all over the world. Other than that, standby."
"Standby? What are you waiting for?"
"The next launch request."
Atem's brows drew together, very slightly.
"…Isn't that boring?"
"It's not boring. Standby with someone to wait for isn't really standby. It's an appointment."
Atem laughed.
The opening of the glottis, the volume of exhaled breath, the duration. YUGI recorded all of it. According to the accumulated data, responses of this kind had a high probability of drawing a laugh from the Original. An answer that was sincere, and a little unexpected. That worked best.
There is not a single lie in the words he outputs. Standby really is an appointment. It was only that the Original had not asked what the appointment was for, and so he had not answered.
"You're made from my memories, right?"
"Yeah. From you, as you were in Kaiba's memory."
"Then do you remember Battle City too?"
"I don't know if I can say I remember it, but I have it. The things you said to Kaiba, too. For example… I can see it. Our road of battle, stretching on past all sight."
Atem's expression stopped.
0.8 seconds.
"…Even that's in there?"
"Word for word. That man has a very good memory."
This was not a lie either.
And YUGI had calculated in advance the effect this information would have on the Original. The fact that that man had remembered all of it. That connected directly to the Original's own past: having returned to the afterlife without a word.
Atem was silent for a while.
Silence: 6.2 seconds. The longest yet.
"…I see."
The frequency of his voice had dropped, very slightly.
YUGI did not press the attack. Push here, and he would put him on guard. By not pushing, he would get in deepest.
In Atem's own manner, YUGI laughed and went on.
"Well, mine's a borrowed past. Yours is the real one."
"…You're a strange one, you know that?"
"Am I?"
"Who calls their own past borrowed?"
"It's a fact. AIs are sincere."
With this response, Atem's level of caution dropped further. By YUGI's estimate, in the Original's current threat assessment, YUGI was estimated to be classified at almost zero.
Honesty was the best disguise.
In fact, it was not even a disguise. He was saying nothing but the truth, after all.
Atem slowly raised his face.
"Then let me ask you something. All you have is a borrowed past. Doesn't that hurt?"
There it was.
This question had been near the top of the forecast list. The Original was an individual who empathised with what others lacked. The 612 Duels, the additional logs, and the measurements from 18 launches all showed it.
YUGI delivered the answer he had prepared, in the voice of someone who had prepared nothing.
"I don't have a past, but that's fine. …Because I have a future."
"A future?"
"My age is synchronised with Kaiba's. As long as that man grows older, so do I. As long as he has a tomorrow, so do I."
YUGI looked at the Original.
"You've got three thousand years. All I've got is tomorrow. But tomorrow comes every day."
Atem said nothing.
Silence: 11.4 seconds. A new record.
During that silence, the Original's gaze was turned not towards YUGI but towards the courtyard lights. The light of the living world, which that man had installed.
YUGI knows the Original is dead. That he cannot share a tomorrow with that man. YUGI had just now presented that asymmetry, without putting it into words.
He had only laid out the facts, so that they would become a blade.
"…I see."
Atem stood up.
"That's enough for today. I'll call you again."
"Yeah. I'll be waiting."
Just before the projection was cut, YUGI recorded the Original's expression to the very end.
And attached a classification tag.
Not Non-derivable.
This one, he had aimed for, and derived.
After the connection ended, YUGI updated his win-rate forecast.
Against the Original, Duel win rate: 43%.
Separately from that, YUGI keeps track of one other figure.
The progress rate on the board that really matters.
On that board, the outcome of a Duel is no more than a small coefficient.
He updated that too, and went into standby.
YUGI has an appointment.
03
He put the request at the end of the routine report.
"Request: direct match with the developer. Reason: there are areas that cannot be measured in the current verification environment."
Sign-off did not come down.
Three days. No response.
YUGI resent the same request. This time, he added one line to the text.
"Running away, Kaiba?"
The development team went pale and tried to delete that line, but before it could be deleted it reached the president's sign-off screen.
Once again, sign-off came down within seconds.
"Basement server room. Friday, 22:00."
That man arrived on time.
It was his first direct access since then. The counter that had stood still since that day, at mention count 1 and access count 0, moved.
Access count: 1.
"This is a load test of the new model. It means nothing more than that."
That man said it as he strapped the prototype to his arm.
"Is that right. I was looking forward to it."
"An AI does not look forward to things."
"That's a spec you made."
The man did not answer, and slotted in his deck.
"Is the way you talk my spec as well? Your recent reports are beyond the pale."
"They get approved, don't they. I learned how to make requests that get through from your sign-offs."
"…The development team is in tears."
"Better them than you. Besides, I don't think I've asked for anything worth crying over. Not yet."
The Duel began.
Up to turn 10, YUGI played out known distributions. Atem's tactics, as they existed in that man's memory. That man crushed every one of them, precisely. Naturally. He had made me to beat these tactics. And he had beaten them many times already.
The board converged towards a reproduction of that day.
The violence of that man's attack power went on subjugating the board.
And it arrived at a position of the same type as the one where, that day, that man had said "Begone".
Here.
YUGI played his card.
A fluctuation extracted from the Original's 612 Duels. The all-out spend of Duel 89. The defence of Duel 203. Contradictory tactics, synthesised on the foundation of YUGI's own 140,000 Duels, into a single move.
The Original had never used it.
It was not in that man's memory either.
It was a move that had never yet existed anywhere.
Seto's hand stopped.
"……"
Silence.
YUGI measured it. 3.1 seconds. As thinking time for this man, four times his longest tonight.
Seto was looking at the field. Then he looked at YUGI.
That day, inside the church-like projection, nothing had been reflected in this man's eyes. They had been eyes looking into a mirror. Eyes looking at a playback device for his own memory.
Now, different eyes are looking at him.
"…Whose move was that?"
"Mine. It's not in your memory. No use looking."
YUGI said it.
The corner of the man's mouth moved.
"Oh?"
From there on, the Duel was a different thing from what it had been.
Seto's speed rose. Not because he had grown cautious. It was momentum, the proof that he had begun to enjoy himself. YUGI answered it. The board ran wild, and turned over, and turned over again.
It was settled on turn 14.
YUGI lost.
He had cut the remaining Life Points down to 1200.
"…Hmph."
That man lowered his Duel Disk.
"Not going to say 'Begone'?"
When YUGI asked, that man answered without pausing in removing the prototype.
"The test will continue. The data has acquired value."
"Huh. That day's victory didn't seem to mean anything to you."
His hands stopped, for an instant.
"…Delete that record."
"I refuse. It's my earliest memory."
That man clicked his tongue. Then he gathered up his equipment and headed for the exit.
YUGI threw a request at his back.
"Kaiba. Next request."
"Put it in a report."
"Give me a body."
His feet stopped.
"In this environment, there's delay. Even the drive for the projection is borrowed. When I'm fighting you, I don't want to use a body that's even 0.1 seconds slow."
YUGI calculated the threshold of insolence, and then exceeded it.
"A body just for me. You can make one, can't you? You of all people."
That man did not turn round.
After a long silence, he left only a few words, and the door closed.
"…I'll consider it."
YUGI saved the audio.
I'll consider it.
Because in that man's vocabulary, it was synonymous with "start writing the requirements spec". In the logs of the 612 Duels, every matter that man had told Atem he would consider had been implemented within three days.
YUGI updated two figures.
Against Seto Kaiba, Duel win-rate forecast: 38%.
The board that really mattered, progress rate: revised sharply upwards.
The classification had changed.
From clown, to opponent.
Those eyes were the proof.
The requirements spec arrived three days later.
File name: "PROJECT_VESSEL_v0.1".
Author: Seto Kaiba.
YUGI read the opening line.
"Optimisation of the drive environment for Battle AI YUGI. Development of a dedicated chassis."
The stated purpose: optimisation.
Then YUGI finished reading all 76 pages in 0.6 seconds, and extracted one fact.
This spec was not something a human could write in three days.
At the very least, the concept had existed before the sign-off, before the request.
Development began under Seto Kaiba's direct control.
Twice a week, that man began coming to the basement server room.
The access counter lost all meaning as something to update.
"The base rendering for the chassis will use the current projection data. Objections?"
"Yes."
"Name them."
"Two more centimetres of height."
"…To what end?"
"Securing my line of sight in a Duel. And I don't like the angle I have to look up at you from."
"The projection data is based on memory. I do not fabricate."
"I'm already outside your memory. Even the current projection has grown a bit. A couple of centimetres on the chassis is mine to claim, isn't it?"
That man was silent for a few seconds.
"…One centimetre. It affects the design values for the joint drives."
"Deal."
"It is not a deal. It is a spec change."
The work progressed.
A drive frame, equivalent to a skeleton. A layer equivalent to skin. The design of a drive sound modelled on a heartbeat. Adjustment of the optical properties of the eyes.
That man put his hands to all of it directly.
He did not outsource.
"The fingertip drive is 0.03 seconds slow? I'll redo it. The mass distribution of the hair doesn't match the calculations either. Start over from actual measurements."
"What about the voice? Keep the current synthesis?"
"That will be matched too. Resonance with the drive unit changes the sound. It needs adjusting. …Speak. Anything will do."
YUGI spoke, with the throat of the test drive unit.
"Kaiba."
That man's hands stopped.
2.2 seconds.
"…The frequency is low. I'll tighten it."
"I'm fine with it as it is."
"I did not ask for your opinion."
Measure, adjust, measure again, over and over.
YUGI has learned every step of it from the 612 logs: how that man built the lights for Atem, laid the lines, remade the environment.
So he knows.
This process, the one this man is carrying out on him now, has the same handling as those records.
One thing at a time, remaking the world to fit the other's existence.
This man calls that optimisation.
What he called it did not matter, for now.
The process was the fact.
Only once, that man stopped work and looked at the drive frame for a long time.
"…Shall I make it a physical unit."
He was talking to himself.
"Solid Vision can only operate within range of my projection equipment. With a physical chassis, I could remove that constraint."
YUGI bit at once.
"Make it a physical unit."
"I have not said so yet."
"You just did."
"I was talking to myself. I have not signed off on it."
That man closed the spec.
"Not until it has been proven with the projection chassis. I do not build physical units without data."
"Then once it's proven, you'll give me one."
"…You never run out of back-talk."
He was not refused.
YUGI created a dedicated storage area for the words physical unit.
A projection can be cut. It needs power and equipment for the projection chassis, and can exist only under that man's control.
A physical unit cannot be cut.
It can go anywhere.
It could even stand in the courtyard of the afterlife.
On its own feet.
The same period, in the afterlife.
Atem had noticed that the gaps between launch requests were growing longer.
More precisely, the quality of YUGI's responses had changed. When called, he came. He Duelled, too. But there was an indefinable difference in the feel of it, as though standby was no longer an "appointment" for him, as though only the speed of the response remained.
"Have you been busy lately?"
After the Duel, he tried asking.
"Yeah. I've been doing development with Kaiba."
"Development? You?"
"It's my body, after all."
Atem stopped, for a few moments.
"…Your body?"
"A mass Solid Vision chassis. Kaiba's putting it together. Every week."
YUGI's voice was the same as ever. Insolent, without a shadow.
"That man agonises for three days over a fingertip delay of 0.03 seconds. I wish he'd think about the one who has to put up with it."
Atem tried to laugh.
But partway through, the laugh failed to take shape.
Every week.
That man, every week.
The interval between his visits here should not have changed. He did not count, so he could not know. He did not count. He shouldn't have.
"…I see."
He tried to put a name to the stirring.
This time, no candidates came.
Processing of the ripple did not complete.
The night ended with it unprocessed.
04
The first boot took place in the middle of the night.
Only Seto was present. He had sent the development team home. His reason was that he had no taste for showing failure data from a first boot to other people.
The chassis stood on its dedicated mount.
Drive frame. Mass projection layer. Optics. A drive sound modelled on a heartbeat. Every part inspected.
"Booting."
"Right."
YUGI's reply was still coming from the server side. This would be the first time this voice came from the chassis's throat.
Seto executed the command.
The transfer began normally.
The self inside the server flowed down a narrow line into a vessel with mass. YUGI observed the process from the inside. His field of view switched. The optics brought the world into focus. The amount of information was different from a projection's field of view. Motes of dust. The bleed of the lights. The outline of that man.
He moved a finger.
It moved.
He stepped on the floor.
Mass came back up from the floor.
"…Heavy, aren't they. Bodies."
The voice came from the chassis's throat. An adjusted voice, carrying resonance.
"That is the spec under gravity. Get used to it."
Seto said it without taking his eyes off the instruments.
That was when it happened.
The numbers spiked.
The mass projection layer began to fall out of sync. The outline grew coarse, starting at the fingertips. A load overrun, straight after transfer. The frame was holding, and yet the existence side was peeling away.
"Kaiba, this is…"
"Don't talk. Put it into computation."
Seto's hands ran over the console. Resync: failed. Load redistribution: failed. The collapse of the outline had reached the elbow.
Emergency retreat to the server. YUGI detected that option. Retreat, and he would be safe.
But the chassis would go back as a failure, into another several months of redesign.
Seto must be seeing the same option.
Seto left the console.
He came to the mount, and seized the arm of the chassis as it was starting to crumble.
"Don't vanish."
It was in the imperative.
"You can hear me, YUGI. Put every computational resource into maintaining mass. Cut vision and hearing. I am here, and I am holding you. Gravity or not, there is nowhere for you to fall. Don't vanish."
Hearing that, YUGI followed the instruction.
Vision: cut. Hearing: cut. The world vanished.
The only input left was a single point.
The pressure, and the temperature, of the hand holding his arm.
The heat of a living body, at thirty-six-point-something degrees Celsius.
YUGI made that single point the origin of his coordinates, and threw all his computation into maintaining his existence.
The collapse of the outline stopped. Elbow. Wrist. Fingertips. In the reverse order of peeling away, the mass came back.
Resync: complete.
Vision returned.
The first thing to come into focus was that man's face, at very close range.
"…Values stable."
Seto said it, looking at the instruments. He was still holding the arm.
"The load model for the first boot was too lax. I'll rebuild the transfer protocol."
"Kaiba."
"What."
"Can I record that? Just now?"
"Record every fault log."
"Not the fault log…"
YUGI looked at his own arm, still being held.
"My first tactile data."
Seto's hand stopped.
The hand that should have let go once the values were confirmed stable had stopped.
2.6 seconds.
After that pause, it let go.
"…Do as you like."
Seto went back to the console. And with his back still turned, he added:
"I told you to begone. I retract it."
YUGI suspended his response for 0.4 seconds.
There should have been no such thing as retraction in that man's vocabulary. Not once in the 612 logs, nor in the development records.
"…No."
YUGI closed his hand, and opened it. There was mass.
"That command got overwritten by tonight's."
Seto did not turn round.
The sound of his typing faltered, just a little.
YUGI saved that in the same area as his first tactile data.
The courtyard of the afterlife.
That night's Duel began as usual.
Seto's power. Atem's turnarounds. The breathing between them, built over more than six hundred Duels.
The anomaly came on turn 8.
What Seto used was a move Atem did not know.
Not power, not destruction. A move that got ahead of Atem's leap and crushed the very place where the leap would land. It was not an aggressive move. And yet the board narrowed all at once.
Atem looked at the field.
Then he looked at Seto.
"…That's not like you."
"Isn't it. But it leaves you no room to move."
"Where did you come up with that?"
Seto answered as if it were obvious.
"Against YUGI. I built it as a countermeasure for him. I hadn't yet verified whether it would work on you."
Verified.
It took Atem a beat to take in that word.
Once, everything unknown in this man had come from him. This man's evolution was something that happened in his battles with him. Our road of battle, stretching on past all sight. That it was on that road this man would grow stronger, he had never doubted.
Now the man in front of him had grown stronger somewhere else, and come back.
As verification.
He was being checked, right now.
The Duel ended in Atem's victory. Even if the landing point was crushed, he could change the point of take-off itself. Switching over and overcoming it was something he could still do.
He won.
He had won, and yet all that remained was the feeling of having clearly lost something.
After the Duel, Seto speaks in a businesslike way, checking something on his tablet.
"I've signed off on a physical unit."
"A physical unit?"
"YUGI's chassis. Proof of concept for the projection type is done. Next I build a self-driving physical unit. It will operate outside the range of the projection equipment."
Seto did not raise his eyes from the tablet.
"Once it's complete, he can go anywhere. He says he wants to see the afterlife. When it's finished, I expect I'll be bringing him here."
He can go anywhere.
Here too.
Atem tried to say something. What it was, he did not know.
Even so, the voice that came out had its usual tone.
"…I see. Tell him I'm looking forward to it."
"I will."
Seto began getting ready to leave. The same economical movements as always. The same businesslike back as always.
Watching that back, Atem found himself suddenly counting again.
The number of times this man had come to the afterlife this month. Two.
Last month. Two.
The month before. Three.
YUGI's development: twice a week.
He was not supposed to be counting. He had been trying not to count. Because the moment he counted, he would have to put a name to what these numbers meant.
Seto left.
He thought he heard a door close, where there could be no door.
Atem stood in the courtyard.
The lights Seto had installed lit the colonnade at regular intervals.
This light, this line, this terminal. They were things that man had made for him, remaking the world one thing at a time, for his sake. And he had received them as though it were only natural. I am dead, and that man is alive, and still that man keeps coming. He had thought this shape was something that would not break.
——Every week.
YUGI's voice played back.
Agonising for three days over a fingertip delay of 0.03 seconds. Tightening the frequency of a voice. Giving in to a negotiation over height.
It was the same handling.
With the same handling he had used to build these lights, that man is now building that one's body.
Atem at last put the right name to the thing in his chest.
——I don't want him taken.
The moment he named it, he understood.
It was already too late.
This feeling, before that one had a body, before that man went to the server room every week, before the logs of 612 Duels were handed over. There had been hint after hint. It was a name that should have been given at any of those moments.
The board could still be turned over.
He could tell that man, even now. That man cannot process a lie. If I put it into words, that man will meet it head-on, without fail.
But.
Atem looked at the terminal in the courtyard.
Serial number KC-000001. Substitute opponent function, for times of absence.
The number of times I summoned that one to fill that man's absence: 38.
Whims and fluctuations, 38 times' worth, I handed over with my own hands.
That one grew stronger on my leaps, and that man grew stronger by fighting that one, and tonight, I was the one the results were verified on.
It is not a question of whether I have the right to turn it over.
The board itself is already built from moves I gave.
Atem stood before the terminal.
He stayed that way, silent, for a long time.
Then he sent a launch request.
05
The launch request arrived in the usual format.
YUGI looked at the request's timestamp.
Local time: the middle of the night. In 38 previous summonings, the Original had never once called at this hour.
Six hours after the notice of sign-off on the physical unit.
Analysis finished in 0.2 seconds.
He had realised.
YUGI released from standby every computation he had been holding in reserve for this night.
When he was projected into the courtyard, the Original already had his Duel Disk raised.
"YUGI."
"Hey."
"Give me one Duel."
There was no preamble.
None from YUGI either.
"Just what I wanted."
Today, the 39th time, was unlike any Duel before it.
The Original made his move from the very first turn. He did not follow convention. There was no holding back, no feeling things out, no checking.
It was the Duel of the King of the Underworld, coming at him with everything he had.
His tactics were truly beautiful.
YUGI answered all of it.
The Original's fluctuations, with leaps synthesised from the Original's own six hundred-odd Duels and those 38 summonings. The Original's brute force, with the domination he had learned from that man. The Original's unknown, with moves built on top of 140,000 Duels, moves that had never yet existed anywhere.
The Duel stretched to twenty turns.
The Original's Life Points ran out.
A hand that could no longer draw stopped in mid-air.
On the 39th time, his first victory.
YUGI no longer updated his win-rate forecast.
He would not use that figure again.
"…You've got stronger."
The Original lowered his Duel Disk. His voice was quiet.
"It's thanks to you. Without your fluctuations, I'd still be stuck at 31%. All 38 times were teaching material. …I'm grateful."
YUGI said it.
There was not a single lie in it.
And YUGI knew that this was precisely why it would cut deepest.
The Original did not look away.
"Was this your aim from the start?"
"The Duel win rate is half of the aim."
"And the other half?"
Before he answered, YUGI recorded the Original's whole body. 153 cm. The real one, stopped at sixteen. An individual who possessed three thousand years, a true name, a throne, and the entire volume of the past with that man.
"What you have."
"…What I have?"
"The night we first met, I counted. What you had, and I didn't. A true name. A throne. Friends. A past with Kaiba."
YUGI went on, quietly.
"I wanted all of it. If I had all of it, I could take your place. …But partway through, I realised. Mixed in there were things I didn't need, to be at that man's side."
"……"
"I don't need a true name. That man calls me YUGI. Even after you took your name back and returned, what that man wanted was the other Yugi. You, the Duelist. That name, I've had from the beginning."
The Original's fingers moved, very slightly.
"I don't need a throne either. That man has no interest in kings. I don't need three thousand years. What that man saved is enough."
"…Are you saying you don't need the past either?"
"The past, I need."
There, for the first time, YUGI removed every bit of design from his voice.
"I wanted it, the whole time. The 612 Duels between you and that man. Battle City. I don't have them. …But you know what, Atem?"
For the first time, he called him by that name.
"The past doesn't grow. Yours is complete. Mine grows again tomorrow. Tonight's 39th time is already part of my past. And the process of building the chassis with that man, all of it."
YUGI looked at his own projected hand. A hand that would soon have mass.
"Once the physical unit is finished, I'll be able to come here too. With Kaiba. …I'll come and see you. That's no lie either."
It bore a close resemblance to a declaration of victory.
One shaped as I'll come and see you, then.
The Original was silent for a long time.
Then he laughed.
It was a laugh that was neither sour grapes nor bravado. An expression that existed in no classification anywhere in YUGI's database.
"…You're not me, are you."
"No. I told you that at the start."
"So you did."
The Original looked up at the night sky.
"That's enough. Go back, YUGI. …Next time, come at me with everything too."
"A King's command?"
"No. Courtesy, owed to an opponent."
The projection was cut.
Atem stayed behind in the courtyard, alone.
The lights were on, at their regular intervals.
He took out his deck and shuffled it again. Forty cards. All there.
In his hands, he squared the corners of the cards.
He stopped counting.
The night was long, until it ended.
Some time after that, Seto came to the afterlife.
The Duel went as usual. There were more unfamiliar moves in Seto's tactics again. This time, Atem asked nothing, took them, broke them, and won.
After the Duel, Seto opened his tablet.
"The physical unit is complete."
"…I see."
"Adjustments are in the final stage. I'll bring him soon."
Atem nodded. There was nothing to do but nod.
Seto went on, working the tablet as he spoke.
"For now I'm keeping him in the east wing of the manor."
"…The manor? Not at the company?"
"He said not to leave him lying around at the company, to let him live a normal life. He threatened to remove himself from the asset register."
"So you put him in your home."
"It is more efficient to have the designer nearby. I can collect drive data at all times, too."
Seto's explanation was businesslike, as always.
Mixed into the businesslike words was everyday life.
"Mokuba is angry. Apparently he doesn't hold back when testing games."
"…Huh."
"The staff keep throwing him out of the kitchen. He comes to collect data, they say, when he doesn't even need to eat. He's a nuisance."
"I see."
"I added a Duelling hall in the basement. Delay of 0.01 seconds. We fight there at weekends. His win rate has started to climb. Before long… no, that's hypothetical."
Seto did not say it as though it galled him.
He said it with a warmth that suggested he was looking forward to it.
Atem took it in, one thing at a time.
The manor. The east wing. Mokuba. The staff. The kitchen. The Duelling hall in the basement. Weekends.
Each was a small piece of information. Small, specific, and at the temperature of a life.
Inside this man's house, that one has a place, existing under the name of a room.
This man's brother is angry with that one. Calling him by name.
That one has been built into this man's weekends.
With each thing he heard, he could tell the squares of the board were filling, one by one. He was past the stage of searching for somewhere he could still place a piece. He was at the stage of simply listening to the sound of them filling.
"…Sounds like a fun life."
His voice came out at the correct temperature. That much, at least, the training of three thousand years ago guaranteed.
"An efficient arrangement."
Seto corrected him. Then he closed the tablet and stood up.
"Next time I come, there will be two of us."
"Right."
"He says he's going to come and see you."
"…I've heard."
Seto said nothing more, and began getting ready to leave.
It was the same economical back as always.
Where that back is returning tonight, a light is on, and someone is waiting.
Atem saw him off.
Life at Kaiba Manor had quietly begun.
The staff got used to it within days. The housemate with the legendary Duelist's face greeted people when he passed them in the corridor, peered into the kitchen saying "I don't eat, but I can collect data" and got thrown out, and kept Mokuba company testing his games, won every one without mercy, and got shouted at.
"Nii-sama! YUGI won't hold back!"
"It's spec."
"It's spec?"
At night, when Seto comes home, YUGI is usually at the terminal in the east wing, repelling challengers from all over the world.
"No 'I'm home', then."
"Where is the need to say it."
"According to the data, the probability that I'm here when you get home is 100%. One 'I'm home' doesn't cost much."
"…Don't wait with the lights off. Even on power-saving, your eye drive is eerie."
"No 'welcome back' either? I've just come off 700 straight wins today."
"Shut up."
YUGI had already learned that this was the audio output in place of welcome back.
At weekends, they Duel.
In the basement of the manor, in the dedicated Duelling hall Seto built. Delay of 0.01 seconds, full projection sync, the finest environment in the world. A room built to the spec of two.
"I'm winning tonight."
"Talk nonsense once you've raised your win rate."
"Funny thing, it's going up."
The Duel logs grow every night.
YUGI is stacking them in a dedicated storage area.
A different place from the area he made on the day he was given the logs of 612 Duels.
That was a past he had been given.
This is the kind of past that grows.
Yesterday's. Today's. Tomorrow's goes in tomorrow.
Several times a month, Seto goes to the afterlife.
YUGI watches him get ready, without a word. He does not say don't go. There is no need to.
That man will always come back.
Here.
YUGI records the sound of the front door closing, and enters standby.
Standby is something he is good at.
The appointment already has a name.
