She is alive, but it is difficult to find the meaning of life. Everything goes with the flow, neither sad nor happy, but there are always some accidents and a heartbeat that burns up the rest of her life in a shorter time than others.
She kept a promise, but became a monster in the eyes of the world. She moved from one city to another holding a classmate's book that was forgotten in memory. She waited for her, but never thought of meeting her again...
He is just a passer-by, but he has become a guest in her heart through his intentional actions. But her heart cannot hold his forever, and parting is approaching. How can he continue a story that has lost its heroine?