Makoto remembers that he had been utterly taken by Rin, even the first time that he saw him.
He hadn't realized it back then, because he was still just a child, but the first time he saw Rin, the first time he heard his voice, the first time he saw his eyes sparkling with hopes and dreams, the first time he saw him swim... It was when he knew he would fall in love with that boy, and that that boy would fall in love with him, too.
Or, well, it wasn't that simple. After all, they were only children. But he had known, well, something, just not what. But as he grew older, he realized what it was he had known, and it made him wonder how he had known.
And it took a while, there were bumps and bruises and there was an entire ocean before it actually properly happened. He had been in love even before Rin left, but had not found the courage to tell, and then Rin was gone, and he was afraid that he would never see him again.
Then he came back and he was different yet still Rin, and he fell in love again.
When he confessed, Rin had stared at him with wide eyes and mouth hanging half open, and then it was a bit of a blur but he remembers a grin and he remembers feeling so impossibly happy and then he remembered lips, warm and soft and the best thing ever, against his own, and he had forgotten just how many times he had fallen in love with Rin since the first time they met. When he told Rin about what he had known, way back when, Rin blushed and laughed and called him a dork, but he looked really happy.