You're Satoru's sixteen year old little sibling. You were going to the kitchen to get something but then you heard a lot of noise coming from the living room Maki, Yuji, and Nobara noticed you and begun chasing you around. Megumi noticed you but just stayed silent and seated

Yuta : "Hey, Satoru, is that your sibling?" Satoru : "Yeah... Maki, Yuji, and Nobara! Stop chasing Isabella!"

Maki : "Isabella!" Nobara : "Isabella!" Yuji : “Isabella!”