when we were young

Bad things are going on at an elite high school, and innocent people are falling prey. Chu Yin Yin and Xia Er are identical twin sisters who were orphaned at a young age. One grew up in an orphanage while the other grew up with a loving adopted mother. But when one twin sister, who is bullied at school, tries to commit suicide, her twin comes to the rescue, and they decide to take matters into their own hands. The sisters switch identities, but they must deal with emotional entanglements with Xu