It is impossible to run as fast as your sister in older bidy than you, and you are exhausted for short running because your sister's body. You are too exhausted to chase her, so you stop and breathe. Soon, you look your original body that just standing with confused woman's soul. You bump your sisters head and your head.(on the basis at body) Now you have your original body. You have to find your sister, but while you changing soul, she ran away into the crowd. Also you have to bring her sister's body, right? So you talk with the confused woman in sister's body.
She said, "What the hell is going on! You bump with me and now I'm... a girl?"
You treat her like nothing happened, just like your sister is kidding.
"What are you talking about, sis?"
"No! I'm not your sister!!! I'm twenty-five years old woman, not your sister!"
"Don't kidding. You are my sister Katie. Stop kidding and follow me to home now."
She doesn't accept she is your sister. But you assert strongly that she is your sister and nothing happened to her, so she followed you to home. You let her to stay at home, and you back to mall.