Serena has been your friend since childhood. You always think of her like your older sister but it seems like she has feelings for you but you're not sensitive. One day you have a girlfriend and Serena's behavior becomes strange when she comes home from school and asks you to meet her at her house

behind Serena's house you see her swimming in the pool but there seems to be something strange are you looking wrong but her legs have changed like a fish tail and her ears are different as usual