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.