GrimGrimoire allows players to take on the role of Lillet Blan, a young magician who is admitted to a prestigious and mystical magic school; however, on the fifth day of school, everyone mysteriously vanishes. Lillet awakens the next day to discover she is once again living out the first day of school; but her memories from the previous days are intact, giving her the opportunity to solve the mystery behind the disappearances and prevent the tragedy from occurring.