Summary: The Professor gives Conan one of Haibara's pull-ups and they begin running tests on Conan. Conan finds the confines of an MRI tube too much to handle but is comforted by a reassuring Haibara.

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Haibara and Professor Agasa waved goodbye to Ran. Conan, wearing nothing but an oversized t-shirt, sat sulking on the couch, devastated by the knowledge that next time she saw him she would be putting him in thicker underwear.

The Professor and Haibara returned to the couch and sat down facing Conan. Haibara wore a smug grin which reflexively caused Conan to pull the sides of his shirt tighter, not wanting to let her accidentally see his unprotected privates.

They sat around awkwardly for a second until The Professor coughed and nudged Haibara. She started nervously, "So have you noticed any new symptoms of the drug?"

Conan said nothing, he just glared at her angrily.

"Hey we tried to warn you the ageing drug might do this but you wouldn't listen! You insisted on taking it!" she argued.

"You should have led with the fact they might make me wet myself!" Conan shot back.

The Professor interceded, "Anyway, whether or not the drug ages you back up, this fixes the problem of Ran thinking you're too mature for your age."

Conan found the knowledge that Ran thinks he's immature less than comforting, but he was able to regain some of his composure and some of his reasoning nonetheless. "So you were expecting this reaction from me?" he asked Haibara. Now it was his turn to smirk. "And you know how? From experience?"

Haibara blushed. "Something like that…" she said.

Conan did some quick deductions. She had left school early on Wednesday and missed the rest of the week. He hadn't thought anything of it at the time but he added the pieces in his mind. "So when you left school abruptly the other day, was that because you…"

Haibara remembered back to that day. She'd tried to hold it the 20 minutes until recess but ended up wetting her pants well before lunchtime. When the class filed out to the playground she stayed behind and had to tearfully ask the teacher to help clean her up before The Professor came and got her.

It was deeply embarrassing but she knew it was time to lay her cards on the table. For science. "I peed myself at school, yes," she admitted.

Conan gave a small laugh but halted when he saw how mortified Haibara was by the incident. "So...how long did the symptoms persist?" he asked.

"They've gotten better," she said. "But I'm still having trouble at night," she added, sheepishly.

"And yesterday she only went through a couple of pull-ups," The Professor added.

The angry face Haibara gave The Professor briefly amused Conan until he realized that he would be going through worse here soon. Then he asked, "So right now are you...wearing?"

Haibara shot an angry, embarrassed glance at Conan. "A woman doesn't discuss her underpants," she said, indignantly.

They all sat around awkwardly again. The Professor moved things along, "Well I think we have some tests to do, right Haibara?"

"Certainly, I'll be interested to compare how the drug affected the two of us differently," she said.

Everyone got up from the couch and The Professor moved to stop Conan. "Haibara, can you set things up? I need Conan's help for a minute," he said.

Haibara nodded and left the room. Conan looked up at The Professor.

"Conan, considering how things are developing we might want to take preventative measures," The Professor said cautiously to the boy. He'd had a similar conversation with a distraught Haibara just a few days before so he knew to tread lightly.

Conan feared what he might hear but he asked anyway, "Like what?"

"Well, Haibara has some protection. Nothing major," he added, seeing the shame creap into the boy's posture. "But if Haibara was anything to go off of you will undoubtedly need it."

Conan began to tear up again. The Professor was his neighbor growing up, he'd known him since the first time he was this age and even before. Normally they talked to each other as piers but he felt so small right now. "Do I have to…?" he asked, tugging his shirt down as if that would protect him.

The Professor immediately saw how uncomfortable this made the boy, so he reassured him. "You don't need to do anything you don't want to do," he said. The Professor, too, was remembering the actual young Shinichi. It had been a while since he'd talked to the regular child but for The Professor it was almost like seeing an old friend. He knew the emotional surge would wear off soon (it always did with Haibara) but he enjoyed kids and enjoyed young Shinichi when he was around. "Besides, Haibara has been facing this alone all week. It would be nice if she knew a friend was wearing one too."

"I knew it!" Conan said under his breath about Haibara's pull-up.

The Professor kept pushing, "And, if you don't need them you can go to the bathroom any time you want," he said with a smile.

Conan smiled, "Alright, I'll wear them. For Haibara," he said. Then he blushed as he became acutely aware of the ongoing pain in his gut. "But...I might need help," he said, shyly.

The Professor nodded. "I've been helping Haibara all week, I understand." he said, smilingly. The Professor made his way to Haibara's room with Conan following.

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In Haibara's room Conan looked around nervously. It was bare, hardly anything to signal it belonged to a 1st grade girl aside from the smaller, occasionally pink shaded furniture. It felt inappropriate to be in Haibara's room without her, especially wearing only this oversized shirt and no underwear.

Meanwhile The Professor was digging around in one of her drawers. "Alright Conan, turn around," he said.

"What for?" Conan asked.

"Well it's easier to put them on your from behind. Anyway, you don't want me accidentally catching that view, do you?" he responded.

Conan gave a small giggle then turned away from The Professor. The Professor, in reality, didn't want Conan to catch a view of Haibara's pull-ups before they were already on. He pulled out a pair, they were mostly white but with shades of pink and a bunny rabbit pattern. Haibara hated them but they were the only ones that fit, he knew Conan would outright reject them.

The Professor came up behind Conan and knelt down. He grabbed Conan's ankle to help balance the boy. "Leg up," he said before lifting Conan's foot and sliding the first leg of the pull-up through. He did this again with his other leg.

Conan was feeling surprisingly content with the whole situation. He was happy to have some kind of underwear below his oversized shirt, even if it was a pull-up. Aside from that he was comfortable around Professor Agasa. The childish side of him felt a sense of nostalgia while the teenage side of him felt comradery.

The Professor pulled the garment up the rest of the way, taking care not to accidentally lift Conan's shirt up far enough to see anything private. Conan felt the pull-up come up and cradle his genitals, feeling instant relief from what felt like being naked below his shirt. After that he gave a slight frown, though. These were notably thicker feeling than his underpants, the padding felt thick on his thighs and the elastic tight on his waist. He gave a small wiggle and cringed as he noted the extra padding on his butt. They were on secure, though.

Conan reached down to lift up his shirt and have a look but The Professor grabbed his hand. "Well, we've kept Haibara waiting long enough," he said, hoping to distract Conan from seeing the girlish design on the pull-up. "Let's get to some tests," he said, pulling Conan out of the room by his hand. Between the thick underwear, the oversized shirt, getting changed by an adult, and being pulled by his hand, the weight of it all was hitting Conan and making him feel particularly childlike. He was thankful that he wasn't crying this time, but he still desperately clung to his shirt with his free hand to keep his pull-up from being exposed to the world.

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In the lab Haibara and The Professor ran tests on Conan. As the tests wore on he began to get his mind clear. 'So what if I'm in a pull-up? It's a medical device, one that Haibara wears as well.' He reasoned to himself. But he feared it would come to nothing when his emotional self took over and he could no longer think straight. His childish spells were becoming more frequent and they were becoming more pronounced. He'd need to take measures to protect his mind while his thoughts were still sober.

As Conan thought about all of this, Haibara and The Professor ran his blood sample, took measurements, tested his lung capacity, and gave him a general check-up. Throughout it all Conan kept tugging the bottom of his shirt, making sure he was well covered. Even if he was fine wearing the extra padding he still had some modesty.

The final step of the tests was an MRI. Haibara waited at the computer while The Professor strapped him in."Remember to be perfectly still," The Professor told Conan.

Conan nodded and The Professor pushed the button to automatically slide him into the tube. As he heard the whirr of the machine belt, his vision left the lab ceiling and instead was replaced by the inner tub of the massive machine. His heart began to race.

'Claustrophobia,' he thought. It wasn't a normal fear of his but any emotion he had seemed to amplify, thus making discomfort into fear.

Haibara saw his heart rate increasing on her monitor. She spoke into the mic, "Shinichi, is everything alright?"

Conan began to breathe deeply to calm himself down. "Yeah, I'm fine," he said. 'I can get through this,' he thought. 'I can control myself.'

Conan kept his focus on his breathing and the scans started. After 5 minutes in the machine he was starting to feel at ease again. Haibara watched as his heartbeat slowed to a nearly normal rate.

But Conan's anxiety piqued again when he felt another familiar feeling. His bladder had sent a message to his brain, express delivery: he needed to go NOW.

Conan reflexively grabbed for his crotch to ease some of the burden but was met with resistance from the straps he was in. This brought back his claustrophobia and he started hyperventilating.

From the other side of the glass Haibara and The Professor saw Conan struggling and saw his heartbeat spike. "Conan, what's wrong!?" Haibara called through the mic, worried about his sudden change in composure.

"How much - - - longer?" he asked through gasps of air.

"Less than 5 more minutes, do we need to pull you out?" she asked back.

"I'm fine, just hurry!" he shouted back. He needed to get his breathing under control. He absolutely didn't want to have to restart but he knew with him struggling as he was they wouldn't be able to get a good read like this.

Conan focused up and started relaxing, using all of his brain power on controlling his breath. It was working fine until he felt something down below.

'Uh-oh,' he thought, at that moment feeling a warm, wet sensation leaving his body and spreading around his privates and to his backside. Conan, in his state of panic, was wetting himself in fear.

He briefly tried to stop the flow but found it completely useless, his body was evacuating all excess liquid he had in him. Conan began to cry as he felt the pull-up swelling up around his waist but with what lucidity he had he realized that this was actually a godsend. He reasoned that, like a child, any new emotion would surpass the previous one that was setting off his fits. Conan had no choice but to focus on his wetting in order to stop panicking.

He focused on his bladder draining and how liberating it was. He hadn't felt pain and the need to burst like last time he'd wet himself while awake, his body had just decided to take the responsibility of staying dry away from him.

Conan felt the last few drops leave him and he gave a small smile. He didn't have to worry about going to the bathroom, he didn't have to worry about changing out of his wet pants, and he didn't worry about being humiliated by anyone who might see him. His little accident just now was his secret.

Meanwhile The Professor and Haibara watched on the X-ray monitor as a substance moved from Conan's bladder to around his waist. Haibara's hand shot to her mouth and she said "I think he's having an accident. Quick pull him out before it ruins your machine."

The Professor gave a small, guilty smile. "We don't need to worry, I convinced him to borrow some of your pull-ups."

"You mean the ones with bunnies?" Haibara asked, giggling. She knew she couldn't make fun of Conan for this, afterall if he hadn't been wearing protection the test and the machine would be ruined. But she could still enjoy this laugh while the microphone wasn't on. Watching Conan wet himself made Haibara aware of how desperate her own situation was, though. She shifted uncomfortably, unable to stop the scan to go find a toilet.

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A few minutes later they finished up the test and unstrapped Conan. Conan sat up, feeling the squish from his bum has he transferred his weight to it. It was uncomfortable but far better than the feeling of cold, wet underwear. He jumped from the table and felt the pull-up sag between his legs. He shifted from foot to foot, trying to get a range of the feeling. His legs, being otherwise exposed to the cool air, welcomes the warmth of his padding.

The Professor went to finish cleaning up the lab while Haibara watched Conan bounce from foot to foot and noticed his mood wasn't just back to normal, it was slightly upbeat. It's the first time she'd actually seen him in a good mood all day.

"So what happened in there to cause your heart rate to spike?" Haibara asked. She knew how the emotional effects of the drug amplified any small discomfort but it was worth asking as a matter of point anyway.

Conan's cheeks flushed red again. He knew he'd have to get changed but he didn't want Haibara to know that he was talking to her while in a wet diaper. "I went to move my hand and it caused my body to have a bout of claustrophobia," he said, speaking partial truth.

"And what caused it to stop?" she asked, trying to bait a confession.

"Uh...deep breathing and relaxing," he said.

Haibara sighed. "Look, if I can't get it out of you then I'll just ask point blank: did you have an accident in the MRI?"

"Eh?!" jolted Conan. He looked down at his bare feet and started lightly kicking the ground with one leg. "Maybe...just a small one…" he confessed, sheepishly.

"And when did you realize you needed to use the restroom?" she asked.

Conan started to get defensive. "I get it!" he said angrily, "I should have went before I got in the machine!"

"That's not why I ask," Haibara said, calmly. She was still vulnerable to mood swings like Conan, but not actively taking the drug made them much more manageable. "I want to gauge about how much control you have left. The MRI showed your bladder was being squeezed from all sides, if the growth continues like this it wont be good. So how long did you hold it for?"

"I don't know…" Conan said, nearly inaudibly.

"Can you give me an estimate?" Haibara prodded.

"I don't know how long I can hold it because I got so scared I wet myself without noticing!" he shouted back, louder than he meant to. He shot up both of his hands to cover his mouth, realizing he had just yelled about wetting his pants. His eyes began to fill with tears and he was feeling himself start to slip away.

Haibara stepped forward and grabbed the boy by his shoulder. "I understand completely," she said. She'd needed someone to understand when she had started having problems days before and she knew she could be that person to help Conan.

Conan looked up straight to her, tears still in his eyes. "Do you?" he asked.

'God, Shinichi is almost cute when he doesn't have that annoying ego with him,' she thought. But she said, "More than you know." Her cheeks flushed red but she knew it was the right thing to tell Conan. "Actually when the test started I realized I had to go but we couldn't just leave you in the tube alone. So I tried to hold it...unsuccessfully," she admitted. She shifted nervously in her damp pull-up.

Conan's eyes widened and his empathy overpowered his shame. Conan smiled at Haibara and Haibara smile back.

The Professor popped his head back into the room. "Conan, Ran is back from shopping. Haibara will help me clean up, she wants to talk to you alone for a second," he said, speaking both to relay the message from Ran and to give the two "children" notice that they need to put on their act again.

Conan groaned, he knew what was coming. Haibara squeezed his shoulders, "It's alright," she said. "Just stay positive and you'll get through this."

"Thanks Haibara," he said, feeling a deep safety in her grasp.