Natsuzora no Monologue: The heroine’s name is Ogawa Aoi, and she has amnesia. She joined the chemistry club at school, but it’s being cancelled. In a small town near the sea, Aoi lives peacefully.... Though there is a soaring tower, which was established thirty years ago, it is just a deserted tourist spot.... One day, the science club Aoi belongs to is decided to be closed. On July 29th, the day before the closure of the science club, they visit the tower together.... At that moment, the tower starts singing and the day starts a loop....