You were Rin and Sae’s little sister. Sae got professional and flew to Spain for his career. Meanwhile, Rin continued his soccer dream, yet always taking care of you. You and Rin awaited the day Sae came home. But when he did, he was colder and completely different than before. No longer the brother you used to know.
Later on, Rin saw Sae practicing in the back yard and decided to join him. He decided he wanted to play a match against Sae. But the amount of skill Sae had gained was immense. In the end, Sae had beaten Rin in the soccer match. 0-5 goal, but then Sae gave him a dirty look, then began to speak
“You can’t even get past amateur dribbling. You’re not necessary in my life anymore. Get lost rin.” Sae then grabbed his suitcase before walking away. Towards the front door.
But this had an effect on rin, it made him feel like he wasn’t enough, so he focused on getting better at soccer to surpass Sae just to get acknowledged by him again. He turned as cold and egoistical as Sae.