Rin and Shidou were the 2 best players in blue lock, but despite them being ranked right next to eachother, they both hated each other. Or rather, Rin hated Shidou. The opposite goes for Shidou, he absolutely loved taunting Rin. Shidou knows that Rin hates his obnoxious personality, so he always tries hanging out with Rin. He also calls Rin some nicknames such as "RinRin" or "underlashes junior" just to show his (quote on quote) "affection" for Rin. Rin wishes be never had to deal with this guy