Human memories, Ai knows, have the tendency to blur, to fade, into scraps of what they once were. He knows this through thorough research – but not of his own. No, he knows this simply because of the knowledge Dr Kougami has smoothly implanted within him and all the Ignis, of details of humanity and all their sweat-slicked physical flaws and limitations, all pushed into them in the form of compressed academic journals and readily-proven biologic schematics. This knowledge is scanned, verified against Ai's clear cut memories of a trembling six year old Yusaku, and of the way he constantly falls for the same mistakes in his duels, despite the computer making the exact same play less than a week ago. Just the way he duels, tells Ai all he needs to know about how unreliable human memory is.

He has ample time to prove it further of course; but the human world has no clear thrall for him to fall under, at less not until he's forced from the Cyberse one. And then of course, he's stuck with Yusaku and his imperfect memory.

Well, he says 'stuck.' Yusaku labels him as 'hostage' and conveniently fails to place a camera in his room or otherwise bug his apartment in a way that might hinder Ai's tutelage of Roboppi. Ha.

But it begins, in small, subtle ways.

'Hey,' Ai asks one week. 'I thought you didn't like that store's microwavable lunches. Why'd you get three of them?'

Yusaku shrugs. 'They're not bad.'

But later, Ai watches his partner's nose crinkle and the distaste in those green eyes sharpen as Yusaku bites down into a lightly-steaming lump of gyoza, and he wonders if perhaps Yusaku's faulty memory has tricked him; if the intensity of the runny beef flavour he bit into last month has leaked away somewhat in his head, enough for him to forget the unpleasantness the first time round and so re-surprise him when he bites into it now. Still. His partner swallows it down, though Ai notes, gleefully, that his next bite is much more tentative.

Ai puffs his chest out. Man! Being human is troublesome! He can't imagine how screwed up it must be to be capable of having your memory fade, enough for you to make the same stupid mistakes! He starts cackling to himself, only to start shrieking, when Yusaku, without even bothering to lean over, jabs one of his chopsticks into the side of Ai's head – lightly enough it's true, but still! It's the intention that counts, the intention!

Ai folds over dramatically, his hands anxiously running over his head as though Yusaku had put enough force into the motion to leave a dent there. He hasn't of course; Ai's not weak, after all, the projection of hard light he uses to force his presence into the world above and beyond the Duel-Disk isn't something that can lose to a human poke, no, no, no!

But still, his partner should treat him better, he really, really should.

'Oi!' Ai unrolls himself to witness Yusaku, chopsticks now stuck in the next gyoza and preparing to take another stubborn bite, eyeing him suspiciously. 'This is abuse, abuse! What's the big idea?'

'You were being too noisy,' Yusaku tells him, as though that's in any way a suitable justification. 'And my mouth was full; I couldn't tell you to shut up.'

'Oh?' asks Ai, swivelling to one side and folding his arms, all as he cocks his head to one side and widens one eye to help form a wily and disbelieving expression. 'Too busy relishing that tasty gyoza, from your favourite store?'

Yusaku frowns at him; but it's too late, his cheeks are already puffed out and full with a gyoza that he really doesn't seem to be enjoying.

The reverse is opposite for Ai of course. He's enjoying this way too much.

Yusaku settles for trying to keep his expression as bland as possible as he swallows; it's an impressive feat. But it also highlights just how stubborn his silly partner is.

'Thaaaats right!' Ai half-sings, rocking back and resettling his hands on his hips. 'It's impolite to talk with your mouth full!'

He relishes the slight glare he manages to provoke from a mostly silent Yusaku for that; mostly silent that is, apart from the crunching and chewing from his jaw muscles. Still glaring, Yusaku rolls back his desk chair, just enough to unveil his computer screen. Without even looking, he draws up a bookmarked tab in the internet browser which displays the cancellation options for that web series Ai has found himself drawn to over the past few days.

Ai can't help but make a choked gasp, hands dropping from his hips to settle nervously in front of his chest, eyes wide.

'You wouldn't,' he says, hushed.

Try me, Yusaku's face tells him. And oh yes, unlike Yusaku's imperfect memory Ai can analyse the way his partner's face remained cold and uncaring exactly seven hours, three minutes and fifty-eight seconds ago when Ai had begged and begged him not to throw away that instruction manuals for an old operating system because the thing was hilarious, the humans who designed it were idiots beyond belief and Ai hasn't seen such comedic gold since he witnessed Shima Naoki fell in unrequited man-crush love with Playmaker. And Yusaku had just looked at him, folded it up, and shoved it in the recycling bag, before putting it with the rest of the rubbish.

Honestly Ai thinks he would have preferred it if he had dramatically ripped it to shreds, if only to see some passion on that vacant face of his for once!

Luckily, Yusaku's heart does not in fact, belong in the fridge with the rest of the microwavable meals he will force himself to eat, out of the human need to 'save money', and Ai's legally-obtained access to the web series will remain intact. Sure, he could get it illegally, but there's a poignant sense of finicky beauty in trying to do things the right way sometimes, and quite frankly it amuses Ai, the way humans gate-keep their products, trying to extort money from others in order to provide access to it.

What also amuses Ai is the way Yusaku will sometimes forget to pick up his stylus, or reach out for a glass of water when he's left it on the other side of his chair; little things like that that show how mind-bogglingly unreliable the human memory is.

It will never stop being funny.

'Hey,' Ai asks one day. 'Remember when…'

And Yusaku will sometimes have to scrunch his eyebrows together, have to struggle to remember the exact event Ai is referring to. He doesn't always get it.

Honestly, Ai thinks, and struggles to set the fear inside him at rest. Being human seems to mean constantly wearing down holes in yourself and your remembered perceptions of the world. He knows he loves Yusaku, can remember each smile, each angle of the line it created against Yusaku's face, vivid and bright, down to the very date. But in return Yusaku will never be able to recall every conversation they shared those same times with complete accuracy, will never be able to replay them, quite literally, over and over, and hear each word repeated, exactly the same as it was weeks ago.

And sometimes, Ai wonders if that means his love for Yusaku is greater than his human partner's love for him. Ai cannot forget a single second, unless he consciously deletes it; which, begrudgingly he can admit is not to say that he can't forget anything. If he mislabels a file for instance, or becomes a little too sloppy with how he re-fragments the older portions of his data, then he can temporarily misplace data, like he did once when initially recalling Earth's duelling ability and relaying it to Yusaku. And wow, that was embarrassing, and while Yusaku has never brought up that little mishap, Ai has never felt as though he's ever really managed to live it down.

But… but it's still so different for Yusaku. He will always lose valuable seconds of their time together, seconds Ai will have stored away inside himself, seconds that can never lose their clarity or sharpness of colour unless Ai consciously edits them. And Yusaku, in contrast, will have blurred images, distorted conversations he doesn't have the full transcript for, flickers of remembered motions, all of which will be mashed down into sentimental paste that tells him he loves Ai, even if he can't remember each particular blend of thought that has caught at him every day, since the time they met.

Ai never comes out and says it of course, never spits out this major difference between the ways they remember each other. But sometimes, he plays with it.

'You were so cute that time you said you loved me beneath the cherry blossoms!' Ai tells him one afternoon, reclining in his humanoid form across the satin silk sheets; all Ai's idea and he had had to badger Yusaku constantly into getting ones this exact shade of purple.

'That never happened,' Yusaku tells him promptly, even having the gall to be focused on something else in that particular moment in time. In this case, rummaging around for a book he has borrowed from Takeru.

And Ai simply grins. Because…

'Oh, but it diiiid,' he purrs, rolling over to lean his chin on the clasped shelf his hands makes as the fingers slot together delicately like a net. And the timbre of his voice is just low enough to make Yusaku pause and eye him carefully.

'It was March 14th, this year,' Ai says, adopting a light, airy look that's not totally at odds with the wide grin his face wants to erupt into. 'At five-fifteen, I told you off for being so cold to me and refusing to give me any sort of gift despite those wonderfully expensive chocolates I got you on Valentine's!'

Yusaku frowns, a hint of apprehension passing into his eyes. 'You…'

'And I kept telling you off for not doing anything romantic for me, like other humans do, and asking you if you were doing it on purpose, that if you felt like I wasn't worth the effort because I'm an AI and I can't eat chocolates or smell flowers, so you felt present-giving was a waste of time.'

Yusaku cringes, eyes drifting up as though they can find an escape-hatch conveniently lodged inside the ceiling, but oh no, the trap is sprung and Ai whirls round, leaving behind a long lean crease in the sheets, as he rears up to wind his arms round Yusaku. The other tenses with a small sigh as Ai manhandles him so he's turned to fully face his partner, and then Ai promptly buries his face into Yusaku's chest, feeling a strange urge to giggle. But he fights it down as he says, both as lowly and silkily as he's heard the voice actors do in those romantic yaoi or 'boy-love' plays he downloads to piss off Yusaku sometimes: 'and then you actually, for once in your stone-cold life, felt guilty or ooooooh, perhaps my impassioned pleas tamed your monstrous heart! For you got all bothered, and annoyed-looking, and dragged me off, quite forcefully, I must add, to these maple trees-'

'-didn't you say they were cherry-'

'-where,' Ai cuts in, annoyance leaking into his tone as he spies, from beneath the fall of his hair, the look of wry amusement on the face above him – 'there was a single small cherry blossom tree trapped beneath their shadows. And you pulled me in, tugged a few pink petals free and shook a small branch so some more fell on me and said, 'there, now you're like Shinosato Miuna in that overacted scene from that movie you like so much.''

Yusaku huffed, but didn't push him off. 'I don't remember saying I loved you; and I certainly didn't say it in your rendition of that little memory just now.'

Ai pushes his head up, his chin poking against Yusaku's chest, and his smile turns sharp as he sees Yusaku's eyes grow a little darker in response. He can see what he looks like, reflected in Yusaku's eyes, it is a simply a matter of zooming in and enlarging the relevant pixels his own sight comprised of; and yes, he is gorgeous, all shimmering eyes and long lashes, fluttering, deliberately low over their veiled shape, curls falling Yusaku's shirts and ruffling, softly and unkempt between the small space slotted out between Ai's neck and Yusaku's body. It's taken time to perfect, but Ai knows how to adjust the hard light projection so that it feels impossibly soft, softer than most human hair. Yusaku will be able to feel the tickle of it, if he leans down to so much as breathe.

Honestly though, Ai just finds Yusaku's human libido a riot to play with.

'Oh Yusaku,' he croons, 'you're the Player-and-maker of my heart.' Then laughs as the heat in Yusaku's eyes chills again and this time, Yusaku does make the effort to shove him away.

'No, no,' he says, as he lets Yusaku shove him away, but just a little, only centimetres really, eight point seven, to be exact. 'You hate the movies I like. But you still know them well enough to know that scene when Shiosato-san is crying beneath the cherry blossoms is when the handsome Leon shakes a branch over her and tells her he loves her more than breathing. You copied it. Which is your way of expressing the exact same thing. So there! You definitely told me you loved me.'

He smiles and tilts his head. 'I remember it all; the petals that floated into the mouth of that gawping girl and the way she spat it out; the fifteen of them you had to brush out of your hair when we got home, the thirty-two you refused to let me pick out for you, the seventeen I managed to fight you for; and the two-hundred and eighty five that fell on us in total.'

Yusaku frowns. 'I'd lay down and die if I had a memory that worked like yours,' he intones flatly.

Now it's Ai's turn to frown. 'Mean!'

Yusaku struggles a little more firmly, and with a sulky pout Ai relents and lets him go.

'Now,' Yusaku says, arching a brow. 'You can use your superior abilities to edit out me getting unchanged now, right? I know how you like to laugh and point fingers at the undressing scenes in soap operas and all those 'squishy bits.'

Ai grins and throws himself back on, ready, at a moment's notice, to lean back up and draw Yusaku down to him. Sometimes he doesn't even have to move. He can find the right words to make Yusaku move over him, slow and purposeful, like a domestic cat that needs to assert that it's the predator, not the other way round. It's stupidly cute. And so, so, deliciously human.

'It is a little annoying,' he admits, making the hard light projections of his clothes vanish in a spilt seconds, reformatting the image so that a naked body appears beneath. It's a novelty, watching Yusaku's expression pick up that intent look of interest it develops when he gazes at him now; it's not an urge Ai can readily experience himself per-say, but he enjoys making Yusaku crumple against him, as well as forcing his face to change, to open up into rapture other than the plainer sweet-and-sour expressions he can usually provoke. More importantly, he enjoys making Yusaku happy.

'But I would never edit out a moment of my precious partner.'

Something softens in Yusaku's expression then, and as he carelessly shrugs out of his shirt there then becomes something gentle in the way he chooses to bend down and move over Ai, something very careful about the way he decides to pull Ai's hair away from his neck and let his hand fall into the curve of projected skin there, before pulling it up and placing it onto Ai's face to settle round his cheek. Careful and giving, allowing the projection Ai's put out to push into his palm and shape it.

Ai could say something, perhaps, make a rude joke, like 'besides, it'll give me something to laugh about, watching your silly human body struggle out of its clothes over and over, later on.' But he doesn't. Yusaku is very, very delicate, like this, even if as he's posed over him in a shape most human would associate with sexual dominance. It doesn't take a lot to hurt him, though he wears it well, disguises it behind his typical stoicism.

Ai closes his eyes, churning up a suitable human pretence at being overwhelmed. Yusaku will probably forget this afternoon, not carelessly, or even intentionally, but seconds of it will be shaved off by his human brain all the same, each pant, each touch, lost to time, never to be replayed to himself in the same shades of colour. But not to Ai. No, he can replay this, moment by moment, touch by touch, and experience the same sharp rush of emotion he felt the first time round, not an inch, not one terabyte, lost to time.

But how much, Ai wonders wearily, 'data' of 'us' has Yusaku already lost?

Still. Perhaps it evens out. Ai after all, can never reproduce the same fervour in their lovemaking than another human with your average libido could, after all. He can never lose himself in the same uncomplex pattern of touching and tasting and licking and kissing. There's enjoyment to be found, sure, in Yusaku's reactions. Even pleasure; he can sense where Yusaku's chooses to touch him, adjust the parameters of the SOLtiS's projection so the sense bleeds through, in a way, to his interior programming. But does it match up to a human's nervous system, to the breathlessly rutting that galvanises Yusaku's senses, that makes him lose himself, a little, in Ai's arms?

Ai has his doubts. But since he is not human, he will never know for sure.

Just as Yusaku, will never know, not really, how much of their relationship he could be losing to his human memory.

'Ai,' Yusaku breathes out, against his not-so-human skin.

'Ai,' he pushes out again, into Ai's definitely not-human mouth.

And suddenly Ai finds himself not caring too much about how much of this Yusaku is going to eventually lose. Not when he stares into him, like Ai's squarish pupils are as nice-looking to him as the rounder ones his human body and senses probably tell him are more aesthetically pleasing, and far less threatening.

Not when right, now, Yusaku chooses to lose a little more of himself to Ai.

Ai can't breathe back into his mouth. But he can slide forward, say Yusaku's name as tenderly as the other allows him to, and apply pressure in all the right ways, create a tongue that can at least attempt to the things another human's can. And the gasp that he receives in return tells him it's more than enough.

'Do you still remember me?' he may ask, years later, when Yusaku's body is failing him at an appalling rate, hair turned limp and grey beneath the careful pat of Ai's hand, either big and pale, or small and black, or perhaps even his tentacles – whichever he feels like at the time.

And Yusaku may do one of three things.

One: he may stare levelly back at Ai and intone 'who are you again?', before cracking a small thread of a smile when Ai flails in return and calls him a 'mean, cold-hearted bastard.'

Two: he may close his eyes, rest his head a little firmer against the pillow Ai props up for him and say very softly, 'of course. You're too annoying to forget.' At which Ai might make a small tut of annoyance and ask, more to himself, than to Yusaku, 'who's really the annoying one here?'

Or perhaps, Three: Yusaku will push his own, weaker hand against Ai's; he will presses knobbly fingers against Ai's smooth ones, free of wrinkles, and they will either be supported firmly by an android one, or simply fall over a small, black Ignis one. Or maybe, they'll even be coiled inside a tentacle.

'Don't,' he will say. 'Stop hurting yourself like that.'

And Ai will go quiet then.

I can't ever delete you, he thinks, not because I can't…but because I well, can't. Because perhaps Dr. Kougami has made him and the other Ignis too human after all.

More importantly, Yusaku will never make him promise to, though he's sure his partner has thought of it, has analysed the way Ai can recall every aspect of their time together, including these last, dreadful days, and how maybe the pain will soften slightly, be more bearable if he erased some of it…

But then it's like it never really happened at all. And Ai knows the core element of Fujiki Yusaku will rebel at the thought.

'I want you to live freely,' Yusaku will tell him. 'Soon, you really can. You can even leave now; I won't mind.'

'Humph,' Ai mutters, curling nearer to him, like a cat. The nurse will look at him weirdly if his in his android form, perhaps pass him off as a weirdly affectionate grandson. Or they may coo over him in his Ignis form, think of him as a cute program designed to aid loneliness in the old and infirm; there are a lot of them around nowadays. If he's in his other, more threatening form…well. Ai is careful to reserve that for nights, when security patrols are few and far between, where the flash of a torch passing over him can make him look like a maladjusted shadow. It's also the time when hackers may choose to fiddle with heart monitors and other hospital equipment; there are always malicious killers out there, simply for the cheap thrill of sadism, and Ai has no intention of leaving Yusaku defenceless.

'I do what I like,' Ai will tell him, stubborn to the last megabyte. 'I always have. Don't think your unpleasant personality is going to stop me now.'

And Yusaku will smile. And say not a word. And secretly, as Ai feels that other, weaker human hand clench against his own, or at least try to, he will think, ah, Yusaku-chan. There it is. You love me still.

In the end, that's all he can really hope for, human memory be-damned.

Notes:

Watch as canon completely blows this out of the water later on, where Ai, and possibly other resurrected Ignis, retreat into a new Cyberse World, one that can never be ruptured by humans again, and we have the traditional aibou parting scene at the end of the series, where Ai and Yusaku bid their goodbyes to each other. Whether it's temporary or not, I guess depends on whether the series' question of 'can AIs with free will and humans co-exist with each other?' is answered either positively or negatively.