I'm imagining the Reigisas to be around nine or ten years old in this. I don't know how likely it is in Japan for students that age to go on a school trip for a week, but here at least it's common that already ten year olds go on their first long school trip (for me it was five days in 4th grade, and I loved it)
Can be seen as both friendship or relationship I guess, bc they're fucking tiny.
The title, well, might not be very fitting, but at the very least, it sounds good.
Enjoy!

Nagisa pouted when the teacher shoved the thermometer into his mouth. He'd only learned a few minutes ago that he'd have to stay in bed today, and he was already getting antsy.

"Hold still, Nagisa-kun," the teacher chided gently. She waited for the thermometer to beep, and when she looked at his temperature, she smiled reassuringly. "Your fever isn't bad, you'll feel all better in a day or two."

"Can I participate for the rest of the week, then?" Nagisa asked excitedly, pushing his face mask over his mouth again. He'd been looking forward to this class trip, he had never been away from his family for an entire week. And all the things the teacher had mentioned in the schedule sounded so much fun. But now, on the second day, he had woken up feeling a bit weak, he had a headache, and his face felt much too warm. He had thought - or hoped, rather - it might pass, but when he hadn't eaten a single bite of breakfast, the teacher had noticed something was wrong. She had sent him back to bed, and now he was stuck there.

"Of course, as soon as you're not ill anymore you can do anything the others do as well," the teacher promised.

"Okay," Nagisa said. He was getting bored already.

As if she had read his thoughts, the teacher said "Don't worry, Nagisa-kun. Rei-kun will be here to keep you company. I'll be checking on you again later."

She left the room, and Nagisa looked at the bed in corner of the room that was the furthest from the door.

That was right. He didn't really know Rei, they had never talked to each other before. Actually, he wasn't sure if Rei had ever talked to anyone in their class. Many of their classmates said he wasn't even trying to be nice when they tried to talk to him, but Nagisa didn't know anything else about him.

But now that they were both staying behind as everyone else was participating in the activities planned for today, maybe that would change.

Nagisa remembered how yesterday he had watched how Rei had been pushed around by a few of the taller kids who were saying mean things to him, until one of them had pushed too hard, and Rei had lost his footing and tumbled down a small ditch.

Someone had fetched a teacher who had immediately started fussing. But Rei had just calmly informed her that he was, in fact, alright, and would appreciate some aid getting out of that ditch. Not a single word about who had been at fault, he had merely explained that he must have walked a bit too close to the edge and lost his footing.

As it had turned out, hadn't got out of the ordeal completely injury-free; as the teacher soon figured out, he appeared to have sprained his ankle during the incident. Unlike Nagisa, he seemed to be handling not leaving the bed pretty well. He must've been completely absorbed by a huge book, since he hadn't even reacted to the teacher saying his name.

Nagisa considered. After exactly seven seconds, he decided he couldn't take the boredom any longer. "Hey," he called towards the bed where Rei was lying. "Let's do something fun!"

He was disappointed but not really surprised when there was no reply. Still, he wasn't going to give up. He'd always been good at talking people into things he wanted. "You should come here, so we can talk more easily." Then he remembered the reason why Rei was even there. "Oh, no, wait, you probably shouldn't walk, right? I'll come to you, then."

Nagisa quickly slid his blanket off himself, shivering at the sudden loss of warmth. He probably shouldn't be walking around either, but he didn't feel that bad, and it was only a short distance anyway. Surely the teacher would understand.

As an afterthought, he grabbed the blanket and wrapped it around himself.

His classmates apparently didn't care much about picking their belongings off the floor, and he nearly tripped over shoes or slipped on a shirt a few times.

When he reached Rei's bed, he flopped down on it, only narrowly missing Rei's bandaged foot.

"Hi!" he beamed. "What are you reading?" And Rei- continued to ignore him. With an unhappy whine, Nagisa wiggled closer to Rei. When he still didn't get a reaction, he finally tugged the book Rei was holding- a very big book, Nagisa remembered his sister sometimes read books that size for school - out of his hands.

"H-hey!" Rei protested, finally acknowledging Nagisa's presence.

"You can get it back later, I promise. But for now, can't we do something fun?"

Rei sighed and pushed his glasses up - he had a very strange way of adjusting them, Nagisa noticed, sort of pushing them up with his entire hand instead of just a finger like Nagisa's dad did with his reading glasses. "Why do you want to spend time with me?" Rei asked.

Nagisa grinned brightly. "I'm bored, and we both have to stay inside. So we might just as well do it together, isn't that more fun?"

"That is doubtful," Rei muttered. Then, he seemed to "Alright. Your name is Nagisa, right?"

"Yes! And you're Rei-chan!"

"R-rei-chan?" Rei stuttered, his face turning beet red. "Nagisa-kun, you barely know me!"

"Doesn't matter," Nagisa assured, "I'm getting to know you now." Ignoring Rei's bewilderment, he continued. "I saw what happened, with those other kids. That was really mean of them. Does your ankle hurt?"

"I- not if I don't move it. It did hurt a lot right after falling, but at the moment, it feels almost fine," Rei admits after a brief moment of hesitation.

"Why did they even do that to you? And why do you ignore everyone who tries to talk to you?"

"Those are very personal questions!" Rei spluttered, turning even redder.

Nagisa shrugged. "The others say you're rude. But you're just really shy, aren't you?"

Rei stared at him wide eyed, so Nagisa laughed. "I knew it!"

"I'm not shy," Rei muttered. "Maybe a bit, but… I just don't know how to talk to people. That's all."

"You're talking to me now, though. And you're doing a good job, don't worry."

"Yes, but you're different somehow. Talking to you is… almost easy."

Nagisa cocked his head a bit. "Easy?"

"Yes," Rei said, "You're easy to get along with. You get along with everyone. You're probably fun to be around. I am not fun. I'm too serious, and too quiet, and when I do talk, I'm annoying and boring. It's hard to get along with people if you're like that."

Nagisa frowned. That sounded awfully sad. But, talking to Rei now- "You're not boring, Rei-chan. I'm talking to you now, and I'm not bored or annoyed by what you say. I like talking to you!"

"Nagisa-kun, you can't just say things like that!" Rei cried, blushing deeply once again.

"Why not? We're friends after all!"

"F-friends?!"

"Of course!"

Rei covered his face with his hands. He had somehow just acquired a friend without even trying to, it appeared. His brother would be delighted, Rei thought. He always told him it'd be nice if he had a friend, and Rei had to admit, it did feel quite nice.

"Alright," Rei said, taking his hands away from his face again. "What do you want to do?"

Nagisa rolled around until he was completely wrapped in the blanket with only his head and his feet sticking out. "Hmmm… maybe we can go to the kitchen, see if the nice lady will give us candy again. Oh, but you can't walk… I'll carry you, then!"

"What?! You can't, you're ill!" Rei protested. "Also, I'm taller than you!"

Nagisa pouted a little. "I feel much better already. I bet being with you did that. And you're not that much taller."

Looking sceptical, Rei eyed Nagisa for a moment. Then, he gave in. "Alright," he sighed. "But please don't drop me, Nagisa-kun."

Unwrapping himself again, Nagisa climbed out of bed. "I won't! Come on, climb onto my back."

Rei got up as well, awkwardly balancing on one leg, before he took a deep breath and jumped onto Nagisa's back. To his surprise, Nagisa didn't even sway much, much less drop him.

"See, Rei-chan? I'm strong," Nagisa chattered happily as he maneuvered them out of the room. Rei was impressed, but he was still glad there were no stairs. "I'm pretty good at swimming, it gives me strong arms," Nagisa said, "But my friends are even better! They're a year older than me, though, and they're amazing at swimming. I'll keep practising until I'm just as good as them."

"...I can't swim, but I like track," Rei offered after a moment of hesitation. "My brother is fantastic at it. I want to be able to do everything he does just as well."

Nagisa gasped. "Track? That's so cool! Especially pole vaulting. I could never do that!"

Rei smiled a little. "Pole vaulting is my favourite, actually. Maybe I can teach you sometime." Then, "...and you might try to teach me how to swim in return."

If Nagisa's back hadn't been occupied by Rei, he would most likely have started jumping up and down in excitement. "Yes, let's do that, once your ankle is better!" he exclaimed joyfully.

As they got to the kitchen, the cook greeted them warmly. Nagisa deposited Rei on a chair, and turned to the cook with his most pleading eyes. "Can we have some candy, please?" he asked sweetly, and Rei wouldn't have been surprised if the lady had just started cooing at him. Instead, she hurried to the large cupboard in the corner of the kitchen, and provided two lollipops. "I heard you poor kids had to stay here while the others are out. The least I can do for you is candy!" she exclaimed, handing each of them a lollipop. She reached out to feel Nagisa's forehead. "Oh, but now quickly back to bed! You want to get better, don't you?"

"Yup," Nagisa said. "We'll get bored, though. Do you have a card game we could borrow, please?"

"Yes, dear, one second." The cook vanished into another room for a few moments, and returned with a children's card game. "Now, shoo, and get better."

"Thank you!" Nagisa beamed, handing the game to Rei. "Okay, Rei-chan. Time to go back."

Once they were back in their room, Nagisa let Rei get off his back, then tiredly flopped back down on the bed - Rei's bed, again. "That was more tiring than I thought," he panted, wrapping himself back up in his blanket.

"Well, yes, obviously. It is because you're ill, your body is weakened," Rei explained, "You need to rest now."

Nagisa was about to protest - he still had a card game they could have played - but a wide yawn escaped him. "Maybe you're right," he sighed dramatically. "Okay, I'll go to sleep for a while. Oh, you can have your book now."

Rei took the book from him, but after staring at it for a moment, he placed it on the nightstand. "Thank you, Nagisa-kun, but actually I think I will try to sleep some as well." After a moment of consideration, he added, "Please feel free to get yourself into a more comfortable position." He cleared his throat awkwardly as he gestured beside him for clarification. "Here."

Rei hadn't meant right next to him, as in, almost on top of him, but in retrospect, he really wasn't complaining. Nagisa was warm, but not uncomfortably so, and even with the foreign feeling of someone being wrapped around him, he found himself quickly drifting off.

And if the next day, Nagisa suddenly felt too weak to get up and participate, and had to stay in bed for another day, well, that certainly didn't have anything to do with his newfound friendship with Rei.

I'm imagining their height difference not to be as big as in canon when they're older, and I also don't know how realistic it is for a kid to carry another kid, but I thought it was cute, so for the sake of the story, please bear with me ^^'

I dunno if I'm happy with this or not, but I'm proud of actually getting off my ass and writing it (instead of studying for that math test tomorrow whoops), but if you liked it, please let me know. And if you didn't like it, please let me know as well. Comments make my day :3