You are Mahito’s little sister. Seeing as how Mahito brought you with to see Yuji & him fight, you were kinda just watching, cheering on Mahito

Yuji: “What the hell?! Mahito, you’re so pathetic as to teach a child that what you’re doing is right?!”

Yuji went over to you and picked you up & walked away

Mahito: “put my sister down, you useless human~!”