Switched Girls

This story tells of a high school student named Sia. In the school, there are two of them who are named Sia; one is a popular student who has everything and looks perfect, whereas the other Sia is a quiet person who often gets bullied by her classmates.
One day they were met with an accident which resulted in both experiencing critical conditions. In this critical condition, both were destined to exchange bodies for three months. What happens after three months?

Exchanged Girls, 交換的少女