Mei Haneda wakes up and finds that she has lost a year of her memory. She is confused but happy when she finds out she has a fiancé, a good job, a best friend whom she thought was dead, but gradually people around her begin to take away the things that are important to her. On top of that, Mei is labeled as a murder suspect and she struggles to find out what happened during the "blank year" to prove her innocence.
