Sorry for the wait but here is the second half of Error. Hope you enjoy.

DISCLAIMER: we sadly don't own Vocaloid.

Rin

Rin rushed down the hallway and to the comfort of her room. She wasn't sure what made her angrier the fact Len would say she was a mistake or the fact that it was completely possible. And now she couldn't get the conversation out of her head. It was all pretty difficult to accept; either she or Len was a nothing but a mistake. 'And all this time they've never even bothered to tell us.'

Flashback

"But they are mirror images; there can't be a mistake in that." Miku says uneasily.

"True, there is no mistake in that, but only one was supposed to be created, the other forced itself to be here, and now that all the fans love to two, and they are so strung to the other, it's impossible to get rid of the one that's a mistake." he sighs.

Flashback End

Rin shook her head as if doing that would rid her of the unwanted information. She couldn't be the mistake. It wasn't possible. She was the stronger of the two mirror images, the cuter one; heck they even put her name first. It was always Rin and Len. There was no way that she was the error and she would prove it.

She walked over to her desk and turned on her laptop. Then opening a file titled Rin+Len she began to watch old videos of her and Len's concerts, show and videos. She carefully looked over both her and Len's performances. There had to be some kind of clue as to who the better mirror image.

But it was no use after almost an hour and a half of watching and comparing performances Rin hadn't found a single hint. She supposed this was the reason as to why they were called mirror images. She and Len were mirrored one another in pretty much most ways and always seemed to perfectly match up when singing and dancing.

Rin turned off her laptop and made her way to the kitchen. She hadn't really realized till now but her head was killing her. 'Damn spending so much time on the computer sure gives you one hell of a head ache." Rin thought to herself as she reached for the orange juice. She took her pouring some in a glass and drinking it. Trying to ignore the pounding in her head and forget about the fact that she could be a fluke. Either that or Len was.

Rin paused as a thought came to her. What if Len was right what if she was the mistake? After all she did have her flaws; she was loud and brash and short tempered. What if she was an error; something that should have been created? Or worse what if Len was the mistake? Rin's eyes widened at the idea. She wouldn't ever admit it to his face but Rin cared quit a lot for her blond counterpart and the thought of something bad happening to him made her stomach drop.

She tried imagining her life without Len. Without his help or stupid jokes or love for bananas. But all she could come up with was blank. A life without Len was impossible to imagine. She couldn't help but feel bad about yelling at Len earlier. She hadn't really meant it; she had just been frightened at the prospect of being nothing but a mistake.

Leaving her empty glass in the sink she decided that she would go find Len and apologize to him. After all from what she had overheard master say one of them was bound to short out. And if there was nothing else to do but wait, the least she could do was wait with Len.

Len

Len laid atop his bed his arms hanging over the side. He had always been good with computer so he had spent the last hour or so trying to get into Crypton's private files on the Vocaloids. It was where they kept all their most important information on the Vocaloids creation and more. But after being kicked of the account twice and running into a message that said he would be arrested if he kept trying to hack into the files, Len gave up. Len just couldn't wrap the idea around his head. How could he or Rin be a mistake? He couldn't remember Rin or him ever having had any problems with their programing or software. They performed well and sang all the right notes, even the really high ones. But now this conversation they had overhead said otherwise. Len let out a sigh; it was weird to think that he could be an error. And he hadn't improved the situation be fighting with Rin. He probably shouldn't have insisted that she was the error. But leave it to his pride and childish sibling instinct to kick in then. But he wasn't all to blame after all Rin fought back. Still he couldn't help but feel a bad about what he said.

Len's thoughts were interrupted by the sound of a knock and the sound of Rin's voice on the other side of his door.

"Len? Len open up we have to talk."

Len slowly made his way off the bed and opened the door for Rin. There he was met with the sight of a slightly pale and sad looking Rin. He ushered the girl inside letting her sit on the bed where he was previously laying down.

"So what is it that you want to talk about Rin?" Len asked trying to still sound somewhat angry at her. After all it was hard to stay mad at her knowing one of them wouldn't always be there.

"It's just that… um…about what I said earlier…by masters door I um…AM SORRY." Rin suddenly yelled making Len jump back in surprise. He hadn't expected her to ever be the first to apologize. Normally it was him who would apologize to Rin, even if she was at fault.

"I didn't mean it Len. It's just the whole idea of one of us being nothing but a mistake has me kind of freaked out." Rin said twiddling her thumbs in together. She always did that when she was nervous or worried. Len walked over to Rin and pulled her into a comforting hug.

"It's okay Rin; I know you didn't mean it and am sorry too" Len said patting her head. "I guess it freaked me out too. I mean being mirror images and all it hard to imagine that there was only supposed to be one of us."

"Yeah..." Rin sighed bringing her hand up to her rub her temple; her head ache was getting worse it was more like pounding in her head. It probably didn't help that Rin could do nothing but worry.

The two Kagamines sat quietly holding one another for several minutes relying on each other for comfort. They would have never thought that their birthday that started off so happily would do a 180 and become so gloomy and despair filled. Heck for all they knew this could possibly be their last birthday together. Minutes pasted before Rin spoke breaking the silence.

"Len do you really think one of us is going to malfunction. I mean there's nothing wrong with us right?" Rin asked not bothering to remove herself from her twin's embrace even though she was feeling a tad warm.

"Rin there is nothing wrong with us. We both have just as much right as anyone other Vocaloid to be here. Look why don't we try to forget about all this for a moment. Why don't we do something else, like sing?" Len suggested.

"Sing? What would we sing?" Rin asked her voice sounding slightly muffled. Len noted the muffled way Rin spoke but passed it off as her being worried and his paranoia. Instead Len began to think of the right song to sing.

"Oh I got it, how about Gemini?" Len asked smiling, he had always liked that song and it had never been difficult to sing. Rin smiled back even though it looked a bit strained and nodded yes.

"Great then let's start." Len cleared his throat and began to sing.

hanarete itemo sōsa bokura wa
ama kakeru seiza no ura omote
sazameku hiru mo setsunai yorumo
sora o koe hikare au gemini sa

Len couldn't help but notice how perfect they sounded together and wonder how one of them could possibly be an error.

futo me ga sameta gozen niji
totemo kowai yume o mita nda
hitori furueru konna toki
dareka dareka tasukete yo

(kono sora ga ochita yōna kanashimi mo)
mune no oku kara kikoete kuru
(tokashite yuku atataka na rhythm sa)
kienai yōni daki shimete

michi ni mayotte fuan na toki wa
me o tojite kodō o kanjite
kajikamu asa mo kedarui gogo mo
kono oto de futari wa tsunagatTER—

Rin stopped singing her eyes wide with shock at what had happened as she sang the last line. Instead of her normally clear and smooth singing voice her voice sounded jagged rough and completely off key. Rin brought her hands up to her mouth as if trying to identify the problem.

"Rin …what was that?" Len asked confusion clear on his features. Why did Rin miss that note, she never had before and as a Vocaloid they were programed to never miss a note within their singing range. So what could have caused her to mess it up?

"I missed that note…"Rin said her voice shaky." I missed that note…I missed that note. I shouldn't have missed that NOTE!" By the end of the statement Rin looked completely panicked. Understanding that missing a note was not a normal thing and was a serious subject that could lead to a dire situation. If only it could have prepared her for what was to come.

"Rin, Rin calm down. It's okay, it's just one note." Len said trying to comfort his now semi hysterical twin and at the same time trying to conceal how terrified he was of what was going on. Masters words about one of them being a mistake danced in his head. But he tried ignoring it pushing the thought to the side and refusing to acknowledge it.

Rin got up from the bed and started pacing the floor, singing different notes. Occasionally she would hit a note that sounded all scratchy and mechanical and that would only cause her hysteria to grow. When she would hit one of these notes she would shake her head and then continue singing and eventually she switched to talking, testing out her voice. But it only worsened with each word she spoke. Soon she couldn't utter a sentence without sounding like a scratched record.

Rin was by now a full-blown storm of fear. She was shaking slightly and appeared to be on the verge of tears. She turned to look at Len and in a quivering crackly voice said,

"Len this isn't okay. Vocaloids don't miss notes. Especially in a song they've sung hundreds of times! This has never happened Len. Never has a Vocaloid sung off key or the wrong note. And for goodness sake just listen to my voice Len this isn't normal. I sound like one of those bad quality CDs. What's wrong with me?" Rin could no longer hold her tears back as she realized that as she spoke she was beginning to sound stranger more like a broken radio then a popular singer. And what's worse was that her head ache was getting worse by the second. Every time Len spoke it sounded too loud. Uhghhh it was like someone was hitting her head repeatedly with a hammer. Rin hissed bringing her hands to her head and holding it tightly. She tried ignoring Len's worried shouts (at least it sounded like shouting) and instead attempted to sooth her head ache by massaging her temples. But at last the pain became too much and as she felt a particular sharp sting of pain in her head she fell to the floor with a shriek, her hands still clutching her head tightly.

"Rin!" Len yelled in a panic. He rushed over to the fallen girl and grabbed her arm to help her up. But as soon as he touched her he let go shocked. Rin's skin was practically burning. What in the name of hell was going on, first her voice and now this? Once again master's words floated in his head taunting him and while Len had begun to understand what was happening he refused to even accept it.

"Rin what's wrong? Rin answer me damn it!" Len yelled he was become more frightened. He could feel panic build up in his throat and making his chest tight with worry. "Rin come on I need to know what's wrong. Rin?" Rin mumbled something that was somewhat difficult to understand through her gritted teeth and scratchy voice. But Len was able to make it out as 'my head'. Len at this point was unsure of what to do. So acting on instinct he picked Rin up ignoring the uncomfortable feeling of her hot skin and began making his way to her room at a rushed pace.

"Rin am going to take you to your room okay." Len said trying to make sure she was still with him. Rin nodded a hiss of pain escaping her lips every now and then. He hurried to her room as fast as he could with the extra weight, unsure of what he would do once he got there. He couldn't call on anyone else for help seeing as they had all left earlier for their own reasons. It was times like these that Len wished that every single one of the other Vocaloids was home and not out reach. He could really use Luka's calm demeanor right now or Meiko's strange but helpful guidance.

Len let out a sigh of relief as he reached Rin's room. Pushing aside her orange door he quickly made his way over to her bed and set her down gently.

Len could only watch her shake and wince unsure of how he could be of any possible help. Her tears which had ceased for the moment had left wet trails down her pale cheeks. After several minutes of tense silence Rin seemed to have calm down enough to speak.

"Len…" Rin mumbled her voice raspier than ever." I guess…we don't have to wonder who…who the mistake is …anymo-"Rin sentence was interrupted as she began to cough violently. Her coughs were harsh and each one would cause her whole frame to shake.

"Rin! Rin stay here I'm going to get you some water okay?" Rin continued to cough but somehow managed to let out an understandable 'no'. Len stopped heading to the door returning to Rin's side a confused look plastered on his face.

"Don't bother Len." Rin said once her coughing had gone down and left her. "There's no point and you and I both know it, am going to short out …and there's nothing we can do about it. Heh…it really shouldn't be a surprise that am the… the error. I've always been the more immature one and the short tempered one. It should have been clear as day considering all the flaws I have. I've never quit been…perfect." Rin took a deep jagged breath only to be terrorized by another coughing fit,

Once Rin managed to suppress her coughs Len took the opportunity to speak.

"Rin, don't say those things about yourself. You should know that it isn't true."

"Oh but it is Len. I mean I was… even the one to…start the fight about being an error. And turns out you were right. Just like always. I mean Len you're such a great person and an even…even better brother." Rin said in her grated voice taking her hand and placing it on his cheek tenderly. More tears fell from her eyes as she gave him a strained smile. Len let out a choked sob as her held Rin's hand listening to what would probably be the last conversation he had with his beloved sister.

"You know this is kind of funny." Rin whispered wincing as she felt another sharp pain in her head.

"Enlighten me Rin, exactly how is this funny?" Len questioned. Somewhere in the back of his mind he couldn't help be amazed by Rin. She was practically on her deathbed and yet she was still being her same old smart ass self, the same strong person she had always been.

"Well… I think it's funny because this reminds me of so many… of our …songs." Rin said.

"How does this remind you of our songs? We die in- oh. Rin that isn't funny." Len said in a somber and serious tone.

"Fine" Rin murmured, "It isn't funny…but it sure is …ironic. It's kind of like proof of life or maybe orphan. Except this time it really will be over for me." Rin muttered the last part quietly. "Do you remember when we filmed the video for proof of life how cold it was and that you tripped and caused the poor camera guy to fall and he caused the other worker in…front of him to fall. Half the crew ended face first in snow."

"Yeah I remember." Len said as he let go of Rin's hand to get lay next to her in the bed. AS soon as he had made he had made himself comfortable he picked up her hand once more. Stroking it with his thumb, his grip never relented. "It's hard not to we had to spend half the day hiding from the angry director. And when he found us in that pile of snow he had to cancel filming for the rest of the day because we were too cold to move. It's a shock we didn't get hypothermia." Len said a soft chuckle escaping him at the memory. He had so many great memories with Rin. He found it was still difficult to accept that he wouldn't be making anymore. How could this be happening to them? They were supposed to be halves, parts to one whole. How could he be complete when he was missing his other half?

"Len… I know what you're thinking and please promise me that…you're not going to do anything stupid once am…once am…gone." Rin's tears had returned full force once more, cascading down the sides of her face dampening her shirt as they fell.

Len couldn't hold back his tears as he nodded his head. Even near her end she was still concerned about his wellbeing. He didn't care what Rin thought because at this moment Len was more certain than ever that Rin was perfect. Suddenly Len's thoughts were interrupted as he heard Rin begin to cough viciously once more. But this time they sounded more devious and harmful. She took her free hand and brought it to her mouth her coughs never ceasing. Yet worse was the fact that her coughs were now accompanied by a thick liquid falling out the sides of her mouth and staining her hands. It was a course liquid that looked like a mixture of oil (most likely from the android half of her) and to Len's utter and complete horror

Blood.

Rin continued to coughed, a terrifying amount of blood becoming present. Rin shivered were she lay feeling cold despite her body's ridiculously high temperature.

"Len" Rin called between her harsh coughs. "There's…there's something I want-COUGH- to tell –COUGH- you." Rin's eyes closed and for a moment Len feared he had lost her.

"Rin, Rin stay with me. RIN, RIN YOU HAVE TO STAY WITH ME OKAY!" Len yelled in desperation he wasn't ready to let her go.

"Len –COUGH- thank you for being… such a –COUGH-WINCE- good brother.

"RIN NO DON'T SAY GOODBYE! STAY HERE RIN, PLEASE YOU CANT LEAVE! RIN!" Len sobbed holding her up a bit from the bed. He resisted the urge to shake her in order to get her attention.

"Len I love-COUGH-you and…" Rin was barely able to finish her sentence bore she felt several more sharp pains in her and mixed with her coughing it was an excruciating combination. Rin winced once more holding back a scream as this time the pain spread through her entire body. A loud crackle of electricity joining the feeling she knew that as she spoke her wires were short circuiting. And that she didn't have much time left but she was going to make sure Len heard her final message.

The entire time Len had continued to hold her begging her to stay, telling her how important she was to him while tears streamed down his face.

"Len don't –COUGH-cry it makes you-COUGH- look like a shota." Rin smiled weakling ignoring the dripping blood on the side of her mouth. Len stopped crying momentarily instead focusing on Rin. He smiled tears still falling down his face before he leaned over and kissed Rin's forehead.

"I love you too Rin."

Rin smiled once more and with much effort took a deep breath of air, "Len …happy birthday…and…and…Thank you." That said another set of horrid coughs raked Rin's body causing her to body to spasm in Len's arms. Rin coughed and coughed heaving up bits of blood as she did until finally the loud crackling of electricity was heard once more and Rin let out one final painful gasp. Her eyes dulled and several numbers appeared in them and once they passed Rin, for the final time gave a tired smile to Len before she closed her eyes and became still.

Len stood still his eyes wide with shock before he finally processed what had just happened.

"RINNNNNNNNN!"

Len sobbed into the shoulder of his now passed twin screaming for her to wake up. Her body was still warm but he knew that soon enough it would be cold from the icy touch of death. He couldn't help but feel useless there was nothing he could do. Nothing anyone could do to bring her back. Rin was gone and all Len was left to do was hold her; his boy shaking from the force of his sobs wishing with all his might he could have her back.

It was two hours later that the other Vocaloids returned home. Where as soon as they entered they heard the sorrow of Len's cries and rushed to find him in a panic.

Only to be greeted with the sight of Len clinging onto his sister tears still falling and his body shaking.

The others soon joined him in his sorrow, Miku the most noticeably as soon she too was weeping.

"Oh Len…" She said before she turned to Kaito for comfort. Luka walked up to the distraught teen patting his head gently before she suggested that maybe it would be best to call master. Len nodded his head in agreement choking back another cry as he remember that only earlier today he and Rin had been headed there to receive their gift. Now the only gift Len wanted was to have Rin back.

In a matter of minutes master appeared at the home a somber look on his face as he caught sight of Len who had refused to let go of Rin no matter how gently or how many times any of the Vocaloids told him he should let her go.

"Len am sorry." Master sighed. "I have to take her with me okay, Len you need to let go." Len refused to acknowledge Masters words and kept his grip on Rin.

"NO! STOP YOU CAN'T TAKE HER FROM ME! YOU CAN'T TAKE HER!" Len screeched as Master attempted to take her body. It took both Kaito and Gakupo to hold back Len long enough for Master to take Rin, muttering another apology as he left.

Once Rin was gone Len stopped screaming instead he just stood there quietly sniffling and wishing that it had been him instead.

6 months later

Len sat on the living room couch quietly staring off into space. The last couple of months had been hard for the young Vocaloid. Without Rin by his side Len had become much quieter and tended to isolate himself from others. He couldn't help it without Rin there always seemed to be missing something. The other Vocaloids had been very supportive and comforting to Len trying to cheer him up. And while he appreciated his friends' attempts and he did at times feel better he still wished that it was Rin comforting him instead.

Lens daydream was interrupted by the sound of the doorbell. Slowly getting up he made his way to the door and opened it to reveal none other than master.

"Hey Len" Master said in his normally cheerful voice. "How have you been lately?"

"Okay." Len said looking at the floor. He didn't really feel like being in the living room and wished that master would hurry about his business so that he could go to his room.

"You're probably wondering why am here so I'll get straight to it. Len I realized that I never actually got around to giving you a birthday present. I know it's been quite some time since your birthday but it took some time to get this gift all patched up and ready for you." Master quickly made his way to the door again and just as he was about to open it tuned to Len once more. "You'll have to forgive me for not wrapping it but I've always been bad at that kind of thing so I settled for putting a bow on it."

Master opened the door to reveal a figure at the door way. Len couldn't see her at first but as soon as she stepped inside and into the light he couldn't contain the look of shock from forming on his face.

The figure was a girl his age. She wore a feminine version of his standard outfit and had short blond hair held back with several clips and a large white bow. She had a slim figure but her most noticeable feature were her blue shining eyes. Len remained speechless tears of joy forming in the corners of his eyes before he rushed to embrace her relinquishing in her familiar scent.

The figure smiled sweetly returning the hug and finally she spoke.

"Hi Len."

"It took me a while to get her memory restored so sorry about the wait." Master spoke in the background.

But at this moment it no longer mattered because she was finally with him. He continued to hold her petting her hair gently.

"Rin" he said softly, "I missed you."

"I missed you too."

Yes at that moment nothing mattered except the fact that once more he was whole and more than anything Rin was back. And this time he was never letting her go.

So there it is hope you guys liked it. You can thank lovinLife for the happy ending, i was gonna leave it sad but lovinlife wanted a happy ending.

So let us know what you think and please review!