Miku belongs to the literature club. One day, she takes charge of writing a scenario of a play staged at the school festival and is given the original book. As she reads it, she gradually feels doubtful about its ending. Several days later, she accidentally falls down into a mysterious fountain that is located deep inside the school and goes to another world. There also live her friends and classmates, but they show different personalities to her. Like this, she starts living at two worlds, but the same story written in the book happens in another world and a tragic ending happens.... When she notices, she comes back to the real world. However, time has gone back and she is given the original book again. She finally understands that the real world and the other world are like a mirror and repeat the same time. She decides to rewrite the story to avoid a tragic ending for the future of her beloved person. Who will Miku save? Who will Miku hurt? No one knows until the end of the story... No one knows if she will be able to save her beloved person....