Rin/Nagisa, gen/friendship, relationship introspection (sort-of), Mostly based on High Speed! because Free! didn't really explore Rin/Nagisa friendship so much.
Part 1 of 2 with this one being about their elementary school. (the second one is the first relay to after their second relay)
Because though Haruka inspires Nagisa, Rin was the one who pushed and pulled him and gave him a sight he couldn't have seen on his own.
Nagisa saw Haruka as an idol. He was this great swimmer who was faster than anyone and who had the most beautiful swimming form. He was hard to talk to and unemotional but Nagisa liked that side of him too. For the whole time they were in the Swim Club, he looked up to Haru and followed him around to see just what makes him so amazing.
Rin saw Haruka as a rival. He was someone faster than him, someone who was accepted more by the water. He swam as if he was a dolphin, a graceful underwater creature instead of a human being. He scowls at Rin and obviously does not like Rin's over-enthusiasm but still, he was interesting enough to talk to. For the whole time he was in the Swim Club, he challenged Haru and pestered him to join his relay, just to feel that excitement of swimming with such an amazing guy.
They both looked up to Haru and followed after him.
But along the way, they found each other. Along the way, Nagisa saw Rin swim and thought "This guy's amazing too!". Along the way, Rin gave in to Nagisa's pleas and decided to watch him practice. Along the way, they were able to look each other in the eye. Along the way, they formed a bond even they could not define.
"Matsuoka-senpai look!" There he goes again, swimming that weird grasshopper form of his. His eyes were wide with excitement as he swam to the side of the pool. "Did you see that? How was it?"
Rin frowned. How was he supposed to say that Nagisa should really just quit butterfly altogether? It just wasn't for him. "You could do better," was his non-committal response, trying to be safe and very much detached. He was scared of this younger boy, even though he does not want to admit it. Nagisa had clear wide eyes that looked into people's souls. And he had an attitude where he just shows everything he feels and thinks to everyone. He was an outgoing person like Rin, but he was very different too. Rin had secrets he could not tell others, had intentions he did not want others to know. Nagisa was an open book, and he makes people want to share their own thoughts. It was scary being around such a person. Rin wants to be careful but there was something about Nagisa that disarms him.
There was a frown on Nagisa's face as he climbed out of the pool. "Still no good?" He pouted, looking down and shuffling his feet. "Mou, I wonder what I'm doing wrong?"
He walks away because he did not want to see that. He cannot stomach seeing Nagisa like that, and the fear just piles up inside him. How can such a small person trigger these kinds of feelings inside him? Besides, Nagisa was a good kid. He was like Gou in so many ways too, and Rin feels like he's the little brother he never had.
---
"I'm going to swim breast stroke for your relay!" Nagisa's expression showed determination and utter confidence.
"What?" Rin raised an eyebrow. "No." He said firmly, diverting his eyes away from those big eyes.
The younger boy pouted and leaned forward. "Why not?"
"Because just a day ago you said you wanted to learn butterfly from me." He tried to look like a strict adult with a no-nonsense tone (though it doesn't quite work with the way his lips were twitching as if almost about to laugh). "I can't have someone so indecisive in my team."
Nagisa looked really sad for a second but then his expression changed immediately into that determined one again. "I'm not giving butterfly up!" He insisted, hands flailing at his sides as he tried to convince Rin. "I'm just leaving it aside until the relay is over! Please, please, please..."
Rin sighed. He has to think fast. He had accepted his fate of not winning against Nagisa when it comes to these kinds of things. "If you win in the next 100 m breast stroke, you can join us." That was a great idea, right? If he wins, he's worthy. And Nanase would join him for sure, since Nagisa seems to be the weakness of that guy too. If he loses, Rin would shake Nagisa off. It's a win-win situation.
---
He did it. He really did. Something inside Rin stirred the moment he saw that turnaround. The way Nagisa swam forward, catching up to everyone with inhuman skill... it was something that left Rin speechless. That was a different Nagisa from usual. That was not the little-brother type kid who excitedly runs around him. It was an amazing athlete with great skill. "Wow..." He stared at the boy as he climbed out of the pool with a huge smile on his face.
"Did you see it? Did you see it?! I won!" Nagisa was excitedly jumping around him. "I'll be in the relay, right?"
"Ah... yeah." Rin still could not get over the image. Where did that Nagisa come from? "I'll keep my promise."
As they went back to the locker room, Nagisa immediately ran to Haru's side. "I did it! I'll swim the relay with you!"
Haruka glanced at him for a second before nodding. "Yeah."
Rin's eyes widened. "You will? You'll swim the relay?!" Was it really that easy?! After all those pestering he did, Haru agreed just because Nagisa said that? Nagisa really is scary, after all...
---
Though Haruka agreed to swim the relay, he still swam freestyle with the other swimmers and he said he would not focus on the relay alone. Makoto said so as well. They had other competitions, and relay was just one of them. They'll do it, but not give it their whole attention.
Nagisa, though, looked at Rin with a big smile and said "I'll do it! I'll focus on the relay!"
Rin couldn't help but smile. Really the little brother type, he thought to himself. "You're a good kid." He patted him on the head and walked over to the other pool. "Let's practice together?"
"Un!" He nodded and followed suit.
---
Rin understood immediately what kind of swimmer Nagisa was. He doesn't learn through his mind. Teaching him through theories and words won't get through. Showing him the exact form helps. Making his body remember helps. Rin had no choice but to swim breast stroke with him.
"Rinrin you're amazing!" His eyes were sparkling with amazement as he looked at Rin who was getting out of the pool after doing a 100m breast stroke. "That was so fast!"
"Don't call me Rinrin." He said, sighing. He frowned at the ground, thinking deeply. He then looked at the boy in the eye (he had to do this every now and then, to get over that irrational fear of someone so cute and small). "What were you feeling when you swam that one time?"
"I just thought I wanted to catch up to them!" Nagisa explained, smiling widely.
Oh. Rin nodded, chuckling a bit. "Race me then. Let's see what you've got."
The younger boy's eyes widened and he couldn't keep the excitement from bursting out. "Race? With Rin-chan?!" He leaned forward, smile so wide it must have hurt. "Really?!"
This time, Rin really laughed. "Let's go." He walked to the platform and waited for him to follow. Once they were both standing in position, he counted up to three and then... "Go!"
Rin's entry was perfect as always. Nagisa was a bit off. As expected, Rin was able to gain a considerable advantage... And then the turnaround happened. At first, Rin was still leading. But he felt it: a shiver down his spine as the smaller figure caught up, as Nagisa desperately swam forward. There was that scary aura again. There was that "that's not human" feeling. Nagisa was having that power-up moment that Rin so wanted to see.
Rin won. But it was a really close fight. And when they finished, he was shaking badly as if he has just seen a ghost. "Nagisa..." The other boy looked at him with a questioning look. "Let's go at it again."
"Un!"
---
Nagisa smiled as he watched Rin practice his butterfly stroke. The older guy probably doesn't know but he really admires him, almost as much as he admires Haruka. While Haruka was someone he admired for a long time now, Rin was this dynamic force that crash landed into their lives and changed each of them. Nagisa thinks that's amazing: that power to change anyone you meet. He seriously wants to have that power. He wants to be able to move people's hearts with a smile.
Besides, Rin was a great athlete who works hard in everything. He jogs that 4 km everyday without fail. He never misses practice and he reads on swimming too. He really wants this and seeing that, Nagisa wants to work hard too.
---
Rin smiled as he watched Nagisa practice his breast stroke. He's been improving a lot since the first time they swam together. The younger guys probably doesn't know it, but the fear Rin felt before has now transformed into respect. He acknowledges the potential Nagisa has, and more than anything, he wants to see it be tapped into its maximum capacity. He deserved that. Despite how people pegged him as a carefree spirit, he was a diligent boy who worked hard for this. Rin wanted him to show off to everyone how good he was. Pride would surge through him as he watch Nagisa swim faster and faster.
Besides, his greatest power was still those eyes. Though he still wants to keep his secrets safe, Rin thinks Nagisa was trustworthy enough. Having him in the team was a good idea. He was pure but understanding, something Rin admires as well. Seeing those eyes staring at him, he cannot help but think "I can trust him".