Hi, minna! This is lil'chrome-chan! I know I'm not well-known in this fandom since I'm only a beginner but I'm hoping to get along with all of you :)

This is my second CoAi fanfic and I made this because some people requested me to write more CoAi story after my Not Sherry's Christmas fic and I give it a shot. This is only an experimental fic since I'm not sure if this is good enough or not. It will be a multi-chaptered fanfic depending on the amount of reviews. And if there's zero review I will erase it :)

Okay then, enjoy the story~

Disclaimer: I don't own Detective Conan

"Kudo-kun…"

Upon hearing his name being called, the shrunken detective knew that the person behind him was Haibara Ai, the only person in this world who shared the same fate as him –shrunken by APTX-4869–.

She trotted back slowly in the graceful click of the Japanese bamboo sandals. When Conan turned, he saw her, in a drape of a velvety silk kimono crowded by a lot of bluish-hue butterfly patter. Indeed, a kimono fitting for a "child". Her purple obi was tied into different-sized ribbons, a side of it large and a side of it small, showing a cute exterior that obviously doesn't fit her character.

"Wh-what?" he didn't realize that he just stuttered, visibly bewitched by her appearance today.

Her eyes however, were seemingly bored as usual.

"You were daydreaming, weren't you? Mouri-san kept calling for you." She said as she pointed at the figure several meters ahead of them, she was waving at them.

"The line has been moving forward during the time you daydream, tantei-san." She teased as she walked forward with him following her from behind.

It was New Year today and Ran decided to bring the Detective Boys to pay a visit to the shrine to offer some prayers for the year. They had been lining up just to reach the shrine because of the mobbing crowd. And now they finally got their turn.

The group of six clapped their hands after they rang the large bell and threw some coins.

Being the first who ended his prayers, Conan peered at the girl beside him who seemed to be looking a little too desperate as she prayed. She was scowling. He wondered what kind of prayers she just offered.

When they had done and went to draw their fortune papers before tying it around the three branches, Conan decided to ask her.

"What did you pray for, Haibara? You look a little too desperate."

"It was nothing…" she answered simply, her expression never wavered.

Conan raised an eyebrow at her.

She acted a little more suspicious than usual.

~o~ WITHERING PROMISE ~o~

Chap 1. The Promise

"Why won't you join the PE class, Ai-chan? It's been two months." Ayumi asked.

"I'm a little tired these days so I can't do any exercise."

"Well it's because you keep sleeping late." Conan commented.

"Ara, I wonder for who do I sleep late every night." She smiled sweetly and it sent shivers through Conan's spines. He obviously knew, if not more than anyone, that she was up late every night because she wanted to finish the antidote, mostly for his sake.

On their way home, the Detective Boys were chattering like usual, mostly about soccer or Kamen Yaiba.

Their days had been so peaceful these days. No Black Organization, decreasing amount of cases, and the others.

As for the shrunken adults who were walking slightly behind them had their own topic of conversation as well. Knowing too well that this isn't something children should be listening to, they carefully control the volume of their voice.

"I think the antidote should be finished in a week. Prepare yourself." She said indifferently in a tone similar to when one say "I had pancakes in the morning".

"The permanent one?!" he yelled in a whisper.

She merely nodded.

Then she smirked, "Aren't you glad? At last you can meet that girlfriend of yours, the one who had been loyally waiting for you all this time." She said sarcastically.

On the other hand, he was too delighted to even react to her sarcasm. If only they weren't in public he might hug her without second thought right now. Thanking her countless times and then promised her that he'll buy a Fusae purse as a form of gratitude.

"Thanks a bunch, Haibara!" he smiled almost too excitedly. She could see his cheeks reddened in bliss.

She couldn't help but smile also.

"You are welcome, Kudo-kun."

"I gotta tell Ran about this!"

Agasa Hakase woke up from his sleep caused by the unbearable thirst. The quiet night, street lamps light bore into the professor's glasses, reflecting a radiant glint as he looked through the window. He could see moths gathering around the lamps, fluttering their wings in considerable speed. Shifting his gaze from the window he noticed that the bed beside him was empty and decided to look for the little girl once he cooled his throat.

As expected, the shrunken chemist was inside the lab, still in her white lab coat and was typing something in the computer. The table beside her was full of mess as Agasa could see the different-colored pills spreading around it. The test tubes were in their rack, all still contented with yet different-colored liquids.

The messy table caught Agasa's attention.

Ai never left her table in a mess, unless when she was very desperate in doing something and wanted to finish it as soon as possible.

Wanting to tell her to stop working and continue it in the morning, Agasa walked in and it seemed Ai was too occupied to notice his presence. That was when Agasa spotted a weird file on the small couch in the room. He picked it up and read it.

At first, he thought that it might be one of the experiment results Ai printed out but he was completely wrong.

It was a check-up result from a hospital.

Whose was that, he wondered?

His eyes widened to their extent when he read the papers inside.

"…Hakase?" the little girl's voice startled him he almost jumped.

"Ai-kun…" his voice quivered.

Her expression was nothing he expected. Not the shocked expression he imagined it to be, nor the expressionless face indicating that she was hiding her emotions…

She smiled a cracking smile.

"Keep it a secret from Kudo-kun, will you?" was what she said with that soft voice.

Stiffly nodding, Agasa broke into tears and hugged the little girl before him. The little girl who entered his life one year ago, and the one he considered the daughter he never had.

One week had passed since Ai told Conan about the permanent antidote. And today was the detective's long-awaited day, probably the most awaited day in his life. The little boy rode on his skateboard and rushed to the professor's house.

Forgetting to knock, he waltzed into the house and cheerfully called for the professor and the chemist.

"Hakase! Haibara!"

He found the antidote on the table in the living room but found no one inside the house.

Assuming that no one was inside the house, he walked towards the kitchen to look at the fridge. Usually, Hakase would leave a message there if he wasn't home.

As he deducted, he found a piece of paper pasted on the fridge.

Reading the paper, he was taken aback.

I'm taking Ai-kun to the hospital. She told me not to tell you but I wish you would come here, Shinichi-kun. I know I'll deeply regret it if I don't inform you about this now.

Come to the Beika Hospital

-Agasa

'What?! Haibara is taken to the hospital? But why?' he mentally tried to recall if she was ill or something but she was still going to school like usual the day before. There wasn't anything particularly awkward with her that time, so why now?

He shook his head.

Rather than thinking about that he should be rushing to the hospital instead.

The room was quiet except for the gradual sound of the IV drip and the beeping sound of the medical monitor. Other than those, it was the sound of her breath through the oxygen mask.

Slowly, her eyes fluttered open.

The blurry slight gradually became clear and she was surprised to find the detective there.

"…Haibara."

"…Kudo-kun…?" she asked, almost couldn't believe what she was seeing.

"Why are you here? I thought I left the antidote at Hakase's house so that you could take without meeting me."

"You only have one month left to live, how do you expect me to think about the antidote…?" he muttered and kept staring at her with mixed emotions in his eyes.

She immediately took that as a sign that he found out. He knew… but how? Could it be the professor?

Ai looked at the side, eyes narrowing, "Hakase told you…" she murmured.

"It doesn't matter from whom I knew it from. Haibara, why didn't you tell me anything? This isn't some joke you used to deceive me with."

"…I'm not ill." Her voice was cold.

"How do you expect me to believe that?! With all the medical equipment here anyone could tell!"

"It's in its worst state now so I have to take IV drip and oxygen mask, it'll get better in no time so you can return to your house now."

"Stop lying to me! You will die in one month and you still don't want me to know? What's wrong with you?!" he shouted.

She kept quiet and silence fell into the room.

He speed-walked towards her and gripped her shoulder, "Haibara!"

Closing her eyes, she gritted her teeth before she removed the oxygen mask before she sat up and yelled back at him, "You're stupid! Why are you here?! You should have taken the antidote, went back to your girlfriend, and then live happily ever after! Then why are you here concerning about someone like me who'll eventually die in one month?!" she said it all in one breathe.

"DON'T SAY THAT AS IF IT'S NOTHING!" he shouted furiously.

She jerked away, eyes wide.

"Why didn't you tell me anything, Haibara?" he placed his face on her shoulder. "You found out two months ago. Why didn't you do anything to prevent it?" his voice trembled, as well as his body.

She bit her lip.

"If I'm even one more month late to find out I might lose you without even knowing the reason…" he whimpered.

"Two months ago…" she spoke.

He brought his head to look at her.

"Two months ago, when I found out about my disease, what do you think it is that first came into my mind?" she asked, her voice low.

He knew she was asking rhetorical question and decided to just listen to her.

A thin smile formed on her lips, "…What if I die before I finished the antidote? If so, then Kudo-kun will never return to his normal life and I won't be able to rest in peace… " she closed her eyes let out a sigh of relief. "But I've finished the antidote now. You don't have to worry anymore. Go back to being Kudo Shinichi and never turn back. Kudo Shinichi… doesn't know any Haibara Ai."

She patted his shoulder, "Once you take the antidote, you will no longer be Edogawa Conan. You will be Kudo Shinichi again, the famous high school detective. Isn't that what you've been wishing for this past one year?"

"…Haibara…"

"That way, I'll be able to rest in peace. To know that the person whose life I've ruined had returned to normal, I no longer have regret."

"No!"

"…Eh?"

"I will take the antidote and so will you!"

She blinked.

"Be Miyano Shiho and spend the rest of your remaining life with me."

"What—"

"Promise me!"

She was still a little shocked but soon she composed herself and closed her eyes as she crossed her arms, "Hai, hai." She muttered.

She let out a sigh, "Who am I to oppose this persistent Holmes?"

He grinned.

Please review :)