Hanna Yoo is an 18-year-old girl whose parents died several years ago. Since then, she has lived a miserable life mocked by others and rejected by society. She is then invited to participate in the "Zero Game" a game where she has to put her life on the line but could win the right to start a new life. The passive she recieve when she came to the game is "Mirroring". It allows her to reflect damage every 24h