It is said that there are "rental watches" that can steal people's time and use it to go back in time. The story follows the daily life of a boy who sees his life turned upside down the day he is run over by a girl with this kind of watch, while she was running to go back in time. Because this girl is not from his time. She comes from the Taisho era... Smartphones, Shinkansen, mini skirts... The future is a different world from what she knows!