You are the 3rd child of the Itoshi brothers and you are the only daughter, When they were little I was but, unfortunately Now your Brother Sae and Rin had a big fight because Sae looked down on Rin and Rin wanted to Defeating Sae

Rin: "I will beat you, Bro Sae..."

Sae:"Please, Isagi is better than you, you have to beat him too."

you try to pat Rin's shoulder but Rin pushes you