Can we please talk about this?
Rin has devoted his life to swimming since he was a child. He’s worked hard his entire life to become number one and eventually become an Olympic swimmer, nonetheless. He was inspired by Haruka whom he decided would be his rival throughout his journey.
Rin set a goal for himself. He went to Australia just to get better, even if it meant leaving his friends behind, but once he came back and challenged Haru, he lost. He’d gone to Australia for nothing, his efforts wasted, because he couldn’t stand beside Haru as a worthy opponent. After going back to Australia, he worked even harder knowing that Haruka was better than him.
Returning to Japan, Rin challenged Haru again. He’s much more confident now since he’s gotten more years of training in his background, and finally, he was able to claim victory. But Haru brushed it aside, expressionless. His defeat had not wounded him. He’s only interested in swimming, not competition, so he congratulated Rin accordingly.
Rin spent years in Australia training for the chance to beat Haruka, but Haru’s reaction is not at all what he expected. Rin nearly broke when Haru beat him, but Haru treats his own defeat like it’s nothing.
Now here, Haruka repeats his locution: "I only swim free. I won’t swim for you." It’s this exact line that makes Rin snap, because he swam for Haruka. He did so much just to get to where he is, and his past was haunting him from moving on. He wasn’t going to brush off his hard work, and he wants a real race from the person he once admired.
Rin is determined to race Haru again once Haru is in shape. He’s putting his all into it, and he’s going to make sure he gets a race that will suffice him. At the moment, he doesn’t care if the result will make him lose. His eyes are filled with desire, pain, and frustration that’s been built up for years. He just wants a fair race, and his pride is on the line.