Disclaimer: I don't' own Vocaloid, Kokoro Kiseki, nor the characters in this story. I've gotten ideas from other Kokoro Kiseki music videos to make this story, and all that credit goes to the youtubers who made/posted them. Though I've gotten ideas from them, there are events in this story that is mine alone. Thanks for reading and enjoy!

Her…

Looking through the cracked, shattered window, she glanced at the enormous cherry tree that was blossoming near the lab. One of the petals came to her from the breeze, and she caught it before, rather reluctantly, releasing it to the winds. Rubbing her arms, she redirected her gaze back to the lab. It was a pitiful sight at the most. A dusty aged computer sat in silence on a faded rickety desk. Wires from the computer curled down it and hid behind a large neglected capsule, where she once slept years ago. Putting her hand over her chest, she slowly sank to the dusty cold tiled floor. Outside, the sun quickly faded below the horizon as a cold draft came into the room, blowing in petals from the cherry tree. Wrapping her long bare legs with her sleeved arms, she buried her face into her arms.

When the crescent moon was out high, the draft finally left. Looking up from her arms, she got up from her spot and began to scoop the small petals into her hands so she could throw them out. As she scooped the last one, which was hiding behind the computer, she noticed something, an aged piece of paper. When she tugged it out of its hiding place, she saw that it was actually a photograph of a family. The two tall smiling parents stood in the back as their twin children, no older than four by the looks of it, stood in front of them, eyes closed and mouths wide open in cute smiles. The picture was so worn that the only color on it was the color of age. Curious, she flipped the photo and saw a few cursive words written on the back.

"Your Heart is where you forgot it," she read her soft voice, the old computer's screen lit up with life, causing her to flinch and drop the photo and the petals. Picking the photo back up, ignoring the scattered mess she made, she looked at the computer in awe as if it was miracle that fell from the Heavens. It had to be because she hadn't seen the computer alive like this for over thirty years.

The screen stayed blank for a long time before loading a message that said,

Rin and Len

The names were strangely familiar to her. Glancing back at the message on the back of the photo and the picture on the other side, she touched the screen with the lightest brush of her delicate fingers. The screen immediately began to glow at her touch, and then, she felt an echo vibrate in her empty chest. A spread of warmth washed over her like a wave, and a sudden burning sensation flooded to her life-sparked eyes. Her hands began to tremble uncontrollably as fresh tears fell on them. She was stunned at the sudden burst of emotion that came over directed her eyes back at the photo, but it was gone, disappeared in the light. What's happening?! She thought as she brought a hand to her chest and, for the first time, she felt something beat. It was mesmerizing to her. Looking around the lab as if it she had woken up from a long dream, it all came back to her: The memories of him.

Him, years back…

Typing away on his computer, he glanced over at the capsule that sat to the right of his work desk. Running one of his hands through his messy ponytailed hair, he used the other to press the enter key on his keyboard. If everything went smoothly this time, he promised himself that he would upload the system to his creation. But, like every experiment, there was always a trial-by-error business that had to be sorted out and after 28 tries, he was sure that it was going to work this time. As he waited for the results, he pulled a worn photograph from his lab coat and looked at it. It was a picture of his family years back when everything was perfect. His tall parents stood in the back as he and his twin sister stood in the front, all smiles and laughs. He couldn't help but smile a little as he remembered the good old days: The days before his sister died and before his parents disappeared soon after. Tucking the picture safely back into his coat, he shifted his gaze back at the computer screen, where he saw that everything went according to plan.

Cracking his knuckles, he made sure that the computer wires were hooked to the capsule before transferring the system to his creation, which rested inside. If it worked, it worked. If it didn't, then the five years he had spent on the project were in vain. Biting his fingernails, he waited anxiously for the transfer to be complete. Then, a notification popped up. It was successful. Feeling a lot of weight lifted off his sore shoulders, he rushed to the capsule's side before opening the door. A cloud of steam rushed out and before him was his creation, a humanoid robot.

For many, building a robot at his age was an achievement that deserved a prize and picture, but to him, it was his way of rewriting a sad bit of history. What if she had survived from the accident? The thought clouded his mind for years after his sister died, and it was only five years ago when he decided to start the project. He knew that building a robot-likeness of his sister was a cheat way of denying the truth, but he wanted his curse to be lifted.

Pulling the head-gear-like-helmet off her head; he picked up his "sister" bridal style and carried her to his chair, where he placed her in a sitting position. Standing back, he took a good look at her, satisfaction written all of his face.

"Rin," he whispered. Hearing his soft voice, Rin opened her eyes and looked at him. Stretching his hand out for her to shake, he told her, "Hey, sis. It's me, Len." She tilted her head to the side, confused. Okay, it was a slow start and Len knew that he had a lot of work ahead of him, but to him, it was all worth it. He wasn't alone anymore.

As the days changed into weeks, Len helped Rin be more like, well, Rin by showing her old photographs of the family, pointing to each person and telling her who they were. He also tried to help her grasp with the new world she was in by teaching her things through books and by doing things outside of the lab. Finally, he tried teaching her songs and how to sing, but he sort of quitted on the idea when she showed no interest to the subject. As he taught her these things, deep down, he knew something was bothering her greatly.

As he watched her practice singing one day, she reminded Len of himself a few years back after the real Rin died from the car crash. He remembered his parents leaving to go on an errand one night after the incident and never returned. Thinking about it shot deep thoughts to his mind. She didn't belong in this world, and that was a fact that bothered him. She might've looked like an ordinary person without troubles on the surface, but deep down, she lacked something that was the basis for any life, a heart.

Suddenly, he felt her cool pale hands on his shoulder.

"Why do you cry?" she asked him, simply. Len gave her a confused look before realizing that his eyes were watering. Looking into her blank eyes, he pulled her into a tight affectionate hug, which she returned with an awkward pat on the back. From that day forth, Len promised that he would help Rin find her heart, even if he had to waste his life on it.

True to his word, he spent the rest of his years helping her. Even when he grew old and fatigued, he still dedicated his time on the project, no, mission.

Then, one day, he skipped the project entirely just to spend time playing with her. Though he was now old, Rin looked as if she wasn't a day older. Well, she was a robot after all, but Len never saw her as that, even in his younger years. In his aching heart, she was still his twin sister. Patting her on the head that cool evening, he said to her in his soft voice, now weak,

"It's time for your system update, sis." Rising from his computer chair, Len shuffled towards the door to go outside, moaning a little as he did.

"Where are you going?" she asked as she got into her capsule, head tilted in confusion.

"I'll be back, Rin. I'm just going out for some fresh air. It won't take too horribly long." Rin nodded before pulling her head gear on and closing the capsule door as she got in. Len chuckled weakly as he opened the door and walked towards the blossoming cherry tree that he and Rin had planted years ago. In the capsule, Rin waited for Len's return for the update, but he never did.

Them together…

Heart bursting, she sprinted out of the lab and towards the cherry tree before wrapping it into a tight hug. Ending it soon later, Rin then ran around the tree like a frantic three-year-old that was recently given sugar. A little while later, she collapsed onto the soft grass before rolling around the flowers that flourished nearby. The gentle wind rained blossom petals on her, and Rin batted them away playfully like a kitten with a yarn ball. Her mind and heart were moving a mile a minute, and her body was probably moving faster than that at the moment.

Is the outside world always this fun? She thought as she sat up, face flushed with happiness. Wiping the grass and petals off of her, she began picking nearby flowers to make crown. Happiness bursting through her rapidly beating heart; Rin tossed her crown into the air before laughing until her throat got sore. When it did, she tucked her red hands under her head before thinking about her past memories, thoughtfully. One stood out from all of them, and it was one that always bothered her. Rising from her spot, she searched around the tree, wondering if she'd find him.

He never did return that day; she thought as she rubbed her hands and blew her breath on them. The happiness she felt earlier drained away as it was replaced with worry. Is he still here? Rin bent down and looked around the tree's roots closely, looking for any traces of Len.

Breathing deeply, she moved away from the tree and began to notice small details that she didn't notice before. Though they weren't any rocks near the tree, she saw them clustered around a root. Seeing them, Rin felt her hands come to her mouth in shock, cold tears streamed past them. They weren't rocks, but the remains of Len, her brother. It can't be possible, she thought as she collapsed onto her knees, her face buried into her hands. But, there was no denying it: Len had his final breaths here.

Looking up from her hands, she said in a choked voice,

"I'm so sorry… Maybe if I was there with you then maybe—" Her throat tightened painfully, so she didn't finish her sentence. Instead, she whispered, "I wish I could see you again."

Hearing her wish, a wide oval portal appeared on the cherry tree's trunk, just above where Len's remains were. Rin glanced at it and saw, to her surprise, Len! Judging by how he looked and the coughing sounds he made, it was the day where he took his last breaths. Jumping to her feet, she rushed towards the portal, screaming her brother's name at the top of her lungs, hoping he would hear on his side.

On the other side, Len, with difficulty, bent down and sat next to the tree, taking in deep breaths as he did. His eyelids began to droop from tiredness, and he began to lose feeling throughout his body as the happy memories of his sister flooded his mind. Is it my time already? His vision began to turn gray as he noticed a portal appear in front of him. Did people hallucinate and hear voices when they were about to die? Struggling, he kept his eyes opened and in the portal, he saw Rin running towards him, yelling his name. Hearing and seeing this, Len rubbed his eyes in shock. Rin was showing feelings for the first time. Her eyes were watering than the usual blank looks he'd gotten from her before. Her voice was high and cracked as she called out his name than the usual monotone voice he was used to hearing from her.

This is my chance, Len thought as he struggled to get to his feet and rushed to the portal as fast as he could in his poor condition. On the other side, Rin punched her hand through the portal, hand stretched out for him to grab. Len grabbed it and, with all the strength he could muster, he jumped through the portal, all signs of age seemed to have slipped away from him. The force of his jump knocked Rin back and pushed her away from the portal as it disappeared.

When the flying birds finally stopped circling around her head, she sat up and saw that Len was sitting in front of her, a smile on his now young face. She didn't know why but her face turned bright red as she looked away, all of the questions she had at that moment seemed to have flown away. When she looked at him again, she saw that Len had stretched his hand out to her. It was a simple gesture, but to her, it said this: Let's play together like we used to when we were kids. Seeing the grin on his face, she couldn't help but grin as well before taking his hand.

The two spent the rest of the night playing, exploring up and down the cherry tree, making flower crowns, and singing to their heart's content. As dawn began to set over the horizon, the siblings leaned against the cherry tree, tired from all their night of fun and adventure. Sighing, Len closed his eyes for a moment to rest. He might've looked young, but in reality (in the portal anyway), he was an old man that was inches away from death.

As he rested, Rin placed a crown of flowers on his head. Smiling, he got Rin's hand and held it tightly. Eyes closed, he told her,

"I was so selfish back then when I built you, Rin. But, when I took the time to get to know you from our lessons, I changed." Rin winced before pulling her hand out of her brother's grasp. He opened his eyes. "Did I hold it too tightly?" Rin nodded before asking him,

"What did I do?"

"You taught me an important lesson. When you're at your lowest point, someone will be there to help pick you back up. That's something I'll never forget." Rin blushed darkly.

"It's not that important." Len shook his head before resting it on Rin's shoulder, eyes closed.

"It was," he murmured in his sleep. Yawning deeply, she closed her eyes as well before singing softly to her brother,

"Thank you for all you've done. From you, I've learned that it's not the differences that define you, it's your choices. That was how I found my heart." He smiled at that before disappearing as the wind came by, transforming his body into hundreds of blossom petals. Stretching her hand up, she managed to grab a petal before they all went away. Placing it next to her ear, she heard a voice, her brother's,

"Your heart was with you the whole time. You just never accepted it 'til now."

"That makes sense," she said as she brought the petal to her chest, her heartbeats calming down. "Thank you." Smiling, she closed her eyes before drifting into sleep. Her breathing eased slowly as her heart gave its final pump.

The miracle of that day lasted only a short moment for the two before it too disappeared into the winds like a blossom petal. In a way, she was his sister, and in a way, he was her brother. What's true is that both souls parted as equals, waiting to meet again in their next life…