One mistake may lead to hundreds of tragedy. The day before Soo Min's big concert day, her college friends Won Ho, Seon Gi, Kim Hong, and Jin Sook gather to celebrate Soo Min. Talking about their old memories and having fun seems like a happy moment of old friends. But soon when Soo Min leaves to the bathroom, Jin Sook starts a disturbing story about Soo Min that she has been sexually abused by her dad and brother after her mom's death. As all friends are shocked, one by one starts to talk about Soo Min's whole secrets as if they know everything about her without knowing Soo Min is overhearing their conversation. It drives Soo Min to the irrevocable revenge with secrets behind.