Work Text:
Playgrounds and Promises
[NagiReo Week 2026]
Day Seven: Different Sport AU | Brought Back Wrong | Childhood
Nagi Seishirō meets the love of his life when he is in first grade.
His family moved to a different city from where he had gone to preschool, so he won't know anyone at this elementary school. He doesn't mind, since he didn't make any friends at preschool. Other kids are loud and confusing. It's easier just to be by himself. That's his plan for first grade, too, but he ends up seated next to a certain Mikage Reo.
The boy is capable of being as loud and confusing as anyone else, so at first Sei plans on ignoring him, even if he does have really pretty purple hair and eyes. He's bright and friendly as he introduces himself to Sei.
"I'm Mikage Reo!" he declares, looking almost expectantly at Sei.
"Nagi Seishirō."
The tiny little eyebrows on Reo's face furrow. "You don't know who I am?"
Well, considering how many children from wealthy families went to this school… "A rich kid?"
"No! I mean, yeah, but…I'm Mikage Reo!" Reo says. They were starting to get curious looks from other children near them.
"Okay." Sei isn't sure what else he is supposed to say.
"You don't know who Reo-kun is?" a brown-haired girl asks. "His family is super important!"
"Oh," Sei responds. "Good for him, I guess."
The girl wrinkles her nose. "You're one of the kids who got in here through a lottery, aren't you?"
"Yeah," Sei confirms. He didn't think that was a bad thing, but the way she said it made it seem bad. Whatever. He just needs these rich kids to leave him alone.
"Come on, Reo-kun, let's go," the girl says, dragging Reo away from him. Sei lays his head down on the table and feels nothing but relief.
However, Reo, despite being surrounded by all their classmates all the time, decides that he wants to be friends with Sei. He keeps talking to him every day. It's confusing. Sei doesn't dislike Reo, but he doesn't understand why Reo wants anything to do with him. Reo's friends definitely don't. They usually succeed in pulling Reo away from him, but one day Reo is just too quick.
"Come on, let's go play!" Reo says during one of their breaks.
"Huh—" Sei doesn't have a chance to protest before Reo is grabbing his hand and tugging him outside.
Sei ends up being dragged around the playground, from swings to slides to monkey bars. He's so overwhelmed and tired by the end of recess that he practically collapses at his desk.
"Sei-chan, you okay?" Reo asks, poking him.
"'M dead," Sei mumbles, his head buried in his arms on the cool surface of his desk. "Reo killed me."
"W-Wait, are you hurt?" Reo's voice is higher pitched now. "Sei-chan, look at me!"
Sei reluctantly looks up to see Reo's wide purple eyes looking teary. Oh. He didn't think Reo would worry. "Not hurt. Tired."
Reo doesn't look any less worried. "Was that too much? I thought we were having fun…"
Sei blinks up at him. He doesn't usually care how other people feel, since it doesn't have anything to do with him. But something about Reo being sad because of him feels…bad. "Not used to playing so much."
"I just thought you looked lonely and I wanted you to have fun too and maybe be friends," Reo rambles.
"Friends?" That was the part that caught Sei's attention.
"If you want to," Reo says, staring hard at him.
"Never had one before," Sei admits. But something about Reo made him feel different. "Okay."
Reo's face lights up in a way that makes Sei feel funny. "Great! You won't regret it, Sei-chan! We're gonna be best friends."
"Wow, my first friend and my first best friend…" Sei is a little amazed.
Reo holds out a hand. "We gotta shake on it to make it official."
"Huh? Okay." Sei doesn't get it, but Reo seems to know a lot, so he could probably trust him. They shake hands. Reo's hand is warm and kind of nice.
"Reo-kun, why didn't you play with us?" The brunette girl who was always hanging off of Reo is giving him sad puppy eyes.
"Sorry, Tamaki-chan, but I wanted to play with Sei-chan!" Reo tells her. "I always play with you guys, but Sei's my best friend, so I wanna play with him too."
"Your best friend? But, Reo-kun, he's…" the girl (Tamaki-chan, apparently) is struggling to find a not-mean way to refer to Sei's lack of money or importance.
"He's super smart and cool!" Reo declares. "He's learning stuff way faster than any of us, and he was super good at the monkey bars, and he said he's never even tried them before!"
Oh. Sei hadn't known Reo was paying so much attention to him. It's super weird, but he kind of likes it? People never noticed him, and when they did, they were always unimpressed. But Reo thinks he is smart and cool. Reo, the boy who is good at everything and liked by everyone. Sei is starting to think Reo was a miracle that he should never let go of, so he grabs Reo's hand and stares at Tamaki.
"Reo's my best friend, too. He can play with me if he wants to. Go away," Sei tells her.
Tamaki's brown eyes widen. "That's so mean! Reo-kun, he's mean!"
"You were mean to him first, Tamaki-chan," Reo says. "If you don't like Sei-chan, then you don't have to be around us."
"B-but—" Unfortunately for her, Reo has already turned away from her and is entirely focused on Sei again, in a way that makes him feel all warm.
"What do you wanna do tomorrow?" Reo asks. "Since I kinda dragged you around today."
Sei thinks about it. "Wanna talk to Reo."
Reo looks very pleased, his smile wide. "I wanna talk with you, too! We can just hangout then!"
"Yay."
By the end of that week, Sei knows way more about Reo than he'd ever expected to. He also meets Reo's scary witch lady, Ba-ya, who is actually really nice, and who talks to his befuddled mother to arrange a playdate for Sei and Reo. He didn't expect to make any friends at this school, but Sei is glad that Reo had been so pushy. Reo is a lot, but he is nice and funny and he is always complimenting Sei. Sei knows they are going to be best friends forever, and then they'll get married so they can always be together.