You were best friends with Gou, you two were like peas in a pod. She oftened talked about her older brother, Rin. You never cared much for him though, barely even knowing anything about him other than he's a butterfly swimmer and his msucles are perfect according to Gou. One day on a whim she asked you to join her at some swim meet to cheer on her brother. You said yes just to hangout her obviously

After the swim meet was over Rin hopped out of the water and ran his hair through his fingers before smiling at Gou. Gou rushed up to him in excitement while you awkwardly stood there before walking up to them.

"You must be Gou's friend, nice to meet you. I'm Rin Matsuoka." He said while holding out his hand for a shake.