Sosuke joined Sano SC in the third grade of elementary school when Rin was already a member and could swim butterfly. Rin forced Sosuke to join and learn swimming butterfly too and Sosuke would always be left saying "Ugh, just shut up". Since Rin was faster and wasn't saying anything wrong or untrue, Sosuke let him trying to teach him butterfly, even though it greatly pissed him off. Their relationship kept being like that for over a year up until Sosuke became a good match for Rin. Because Rin was the one who taught Sosuke how to swim, things like the timing of their breaths or the way they moved their arms were exactly alike and, as Sosuke once stated, he couldn't seem to shake it, it was just ingrained then. During the time he was at Sano SC, Sosuke and Rin's relation was having competed for being the representative, formerly they certainly had a relationship that could be called friends.
When Rin said that he wanted to go Australia and when he said that he wanted to swim at Iwatobi SC, just saying ‘I understand’ while he was half shocked, he didn’t try anything like halfheartedly keeping him back or pressing questions. Sosuke kept being someone who understood Rin well until the end.
In High☆Speed!, Rin stated that it’s better if he's not on the same team as Sosuke because they "understand each other too well". He says that Sosuke’s even more theoretical than he is and that they often quarreled. They settled on it that the faster way is always correct, but their competitive spirit wasn’t half-baked anymore. He said that he doesn't hate him. Rather, he still thinks of him as the person who understands him the most, but sometimes it becomes difficult to be together. When he ends up understanding Sosuke's feelings, he ends up not being able to say the things that he wants to. He could no longer seriously go up against Sosuke. because he was that one friend who got him way more than his other friends, and that made Rin feel uncomfortable. He said that that was not a friend, but like an alter-ego (you don’t like or hate your alter-ego).
Even though Sosuke and Rin didn't see each other in such a long time, they're still great friends. Sosuke likes teasing Rin, as seen when Rin asked him if he's going to stop swimming and has a special type of a handshake with him. Sosuke is very concerned about Rin and his future and dislikes everybody who stands in Rin's way to success, including Haruka, who, according to Sosuke, did "something Sosuke would never do".
Dive to the Future
Sprouting Dive Start!
- Sousuke starts writing a letter to Rin but gets stuck
First Swim in a New Country!
- Rin has a picture of him and Sousuke on his desk from their relay last year
- Rin thinks back Sousuke telling him about Ikuya
- Rin mentions to Natsuya how he wants to swim with Sousuke again.
Interference of Loss!
- Sousuke asks Gou not to tell Rin that he can swim again, since he wants to tell him himself
On AO3, SouRin is the most written ship for Sousuke and the second most written for Rin. It is also the fourth most written ship in the Free! tag.
Screenshots and Gifs
|slash||HiyoIku • IkuHaru • MakoHaru • MomoTori • NatsuRin • Reigisa • Ringisa • RinHaru • RinRei • RinTori • SouMako • SouRin|