Hey guys! You know, I realised that you guys really liked this story, so… After much deliberation, I revised it greatly. Tell me if it's better/worse than it used to be.

Disclaimer: I don't own Vocaloid, the program, nor the whole thing itself. I didn't create Kokoro, and neither do I own Len and Rin.

When someone dies, they are sent to the afterlife.

Anything with a heart, anything with a mind, anything with 'kokoro'.


"What do I mean to you?" He would ask as he tinkered with the program he was making.

"I do not understand, professor." She would respond, her voice flat, emotionless.

"I've told you before, I'll tell you again, call me Len!" He would reply, always the same way. Always annoyed that her program couldn't register this one thing, his name. Always using that cold, distant formality. He could always change her program, of course, but...

It didn't feel right to change her, to take away what little she had that was her.

"I do not understand, Len." She would correct herself, though the change was only temporary. But it was to his delight that, at least for a short time, she could remember.

"How do you see me, I guess… Well, not really but…" A frustrated sigh struggles not to show. "Forget it. Just stick with 'How do you see me'." He would sigh, feeling a bit defeated somehow. Why did he subject himself to this? Starting this conversation, again and again, with some vain hope that it would hammer home. That she would realise... something. Something he didn't know, anything!

"You are my creator, you gave me birth, for that I am very happy." She would chatter on, a radiant smile settling on her face. It wasn't real, though, just a protocol built in to her system. He doesn't like to make her pretend, if he could only bring himself to, he would erase it. But as a young boy he had been hungry for someone who would stay by his side, someone who wouldn't leave. Anyone.

"You know very well what exactly I mean. How do you feel? Because you know what I think, don't you? You remember?" A horrible twisting feeling would appear in his stomach, he hated himself for this.

"Yes, Len." She pauses for a second, running a search through her memory banks to bring up that piece of information. A thoughtful look blossoms on her face, for about only as long as it took to bring it up. Another protocol in her programming. "You love me."

How many times before had he asked that question, to hear those words tumble from her? Some small pleasure came to him, hearing those words. But the elation never lasted long, as guilt soon followed, wondering, 'How could I use her like that?' Sometimes he asked even asked himself how he could love a blank slate, a robot with no heart. It should have been impossible. But he did, somehow.

A memory flashes in his mind, and he remembered teaching her to sing, how terrible she had been at first. Her tone either too flat, or too sharp, and she couldn't keep beat. But if there was one thing that she was able to learn, that would stay with her, he made sure, it was music. He loved music, and he had thought to himself, as a kid, 'How cool would it be I could teach her how to sing?'

He chuckled, a smart blot of happiness in a life that frustration had defined.

A long, hard road it was, teaching her. But her voice now… It was beautiful, it was like nothing he had heard before, however, she could only imitate the music he played, the same tone, the same emotions expressed in her voice. But it wasn't her own. It was missing something, always missing something.

"What is 'love'? I do not understand… Run love." As soon as the words would leave her, her eyes would flash up, blinking steadily, as she struggled to try to run the program, efforts only ending in error. "Len, please explain 'love'."

That frustrated sigh would appear again. "Run the word in your search program, Rin."

Rin, he had thought himself so clever, to name her that. Left and right, so naturally together that they could never be apart. She was made to never leave him, to be his companion through thick and thin.

"Search : Love... Found, 1209 terrabytes of credible research. Scanning... Love, fond platonic or romantic feelings of deep standing in a person. Confirm, this is what Len feels for me?" She looked up, a smug look on her face; he could almost believe it was real. He wished he could believe it was real. But it was yet another facet of her programming showing through.

"Exactly that…" Unconciously, he would run a hand through his blonde hair as he found yet another flaw in his program he was writing. Telling himself that it was impossible, that it would never work. That it was a waste of time.

"I am flattered, professor." The cold distant title looms over him again, pulling him back to reality.

"So it's back to that, is it?"

Third miracle… Not yet… Not yet…

Thank you for the times we spent together.

Decades had passed, he was now an old man, but… he wasn't lonely, he had Rin, always. But he was dying now. And.. and.., he felt strangely unfulfilled. He had never gotten that program to work properly. It was almost finished now, but it was too late. Much too late...

He motioned for Rin to come to him, tremors ringing through his hand, it was going to be soon. He had to remind her.. His last order before death, meant to preserve her.. He could not bear it if he had caused her demise.

"Rin..." Barely a whisper came out of his mouth, almost unintelligible, but it was nothing against her word recognition system. "Never... Never ever run the program in my computer, under no circumstances, do you understand? It will be too much for you to handle... You'll shut down."

What it was that he had worked tirelessly to make, was a heart, a mind, all for her. Real emotions, sadness, pain, happiness, regret... Love. But there had always been problems, countless errors. Whenever he would run it on a test subject, they would always be alive, truly alive, surprised and utterly marveling at the world before them, and their new found appreciation of it all. But it was only for a few minutes, shortly after their epiphany, they would shut down, and any tries to restore them were complete and utter failures. Had he killed them, inflicting this upon them? Bringing them to life, knowing full well they would be stuck down?

It was just too much for them.

She would never comprehend what it was to truly feel… But, he honestly appreciated the time her spent with her. To have her by his side as his life slipped away was all he could ever dream of.

"Yes, professor." He had given up correcting her now, it didn't matter…

"Rin... Sing for me one last time." As he died, he wanted to hear her voice, her beautiful voice.

"Yes, professor." She replied, searching her song bank through a set of filters, to pick a song. She would click her tongue as she did so, a mannerism picked up over the years, though he didn't know how. Then, she sang, and it was beautiful. But as always, it was missing something, always missing something.

He was crying silently, he had wanted to give her that something before he died... She deserved to know.

Hundreds of years had passed since his death, but after all this time, she was still running.

Some would call it a miracle that she was sill running, that the power in the lab was still running, that both had survived this long.

Curiosity coursed through her circuits, she felt it, and it registered somewhere within her that she shouldn't... but she did. She wanted to run the program, the one thing that would supposedly stop her from running. What could it have been that was too much for her to handle?

She turned the computer on, another miracle, that it was still running. Almost hesitantly, she brought the program up, and connected herself. All she had to do was press a button, and it would stood before the computer, weighing the options thoroughly, percentages and outcomes, and eventualities. It took days for her to come to a decision.

She pressed the button.

And it was a wonder, infinite.

She was still singing, as he lay there, waiting. He could feel it, it was going to be soon... so soon...

"Receiving message? From…the future. Is it.. Me?" She exclaimed, interrupting her own song, his eyes fluttered open to look at her.

"What?" He replied, one of his last breaths.

Her voice poured forth, but it was different.

It was heartfelt, she was singing from the very bottom of her heart... Heart? His own jumped, such excitement for a man on the brink of death. He couldn't believe it. His mind rushed to connect the points, she must have activated the program. Except she was still running, was he wrong? Should he have run it on her all those years ago?

The words that came from her mouth warmed him, thanking him for the life that he gave her, thanking him for everything.

He reached out to touch her, and she smiled.

"Thank you, Len."

It was with that one sentence, his soul was free to go, he finally went in peace.

'Why don't my tears stop?'

He was dead, had been for years really. But... It seemed only to hit her now. In those few minutes, she had lived more than she ever had in her entire centuries before this.

She fell to her knees, body shaking, tears falling, how though, she didn't know.

Now, now she knew, she knew what it was to be feel. Happiness, warm and bright, and ticklish. Sadness, painful and regret filled, enveloping and surrounding. Love, something undefinable. In minutes, what had eluded her for centuries had finally become clear.

She was smiling, despite all the tears, despite his death, despite that she missed him, despite everything. She smiled because even if he was gone, she knew now. She could understand him, and all the strife, and pain he had gone through, for her.

It was then that her joints seized up, and the light of life left her eyes. There she stayed, clutching her heart, and on her knees. Though her eyes were empty, that smile, her beautiful, real, smile remained.

She was surprised, shortly afterward, to find herself standing up, able to move, and not that there was an afterlife... but that she was in it. A robot, something fake, pretend, something that had never really lived, other than those few minutes at it's end.

Looking around, she wondered if she in the lab. She wasn't sure. It looked a bit like it, but she could not think of a time in recent memory where it had clean, and pristine. It looked as if someone had been taking care of it.

Her heart swelled when she saw him, [she faintly expressed surprise that she actually had a real beating heart].

His own heart accelerated when he saw her. He had been waiting, hoping that when she did finally shutdown, she would come here. But it had been so long… He had begun to doubt himself.

Seeing her now, all he could do was affirm all that he knew.

"I love you."

It came out so easily, and he almost couldn't believe this, it was too perfect.

A million bad ends came to his mind, what if he didn't love her, what if he didn't like her personality.

He pushed them away, closing the gap between them, taking her in his arms, and pressed his lips against hers, in such a way that made her jump. All that he had been in life, and all that he became in death expressed in that gesture, and she could feel it.

Pulling away, he looked at her, flushed and embarrassed the both of them. It dawned upon her that when he said he loved her, he didn't mean just 'in platonic standing.' But it was hardly a bad thing, and that indefinable emotion came to mind, she realised that she wasn't feeling very platonic towards him either.

He grinned, still watching, and whispered in her ear

"It really took you long enough."

I'm also planning to write a second chapter, detailing Len and his stay in the afterlife before Rin appears, if you guys would like, and if I can figure out a way to make it work nicely.

Reviews, as always, are appreciated!