In the town of Kurashiki in Okayama Prefecture, Kokone Morikawa, an average high school student, lives with her unsociable mechanic father near the vicinity of the Seto Ohashi bridge. Even though she should be studying diligently for her university entrance exam, Kokone is constantly falling asleep, a trait she proudly considers her own special talent. Due to some strange reason, Kokone recently starts to have the same dream over and over again, and it usually involves warring machines. Three days prior to the 2020 Tokyo Olympics, Kokone`s father is suddenly arrested and brought to Tokyo. Despite her father`s brusque and unfriendly personality, Kokone doesn`t think that her father would commit any crime. So, together with her long-time friend and University student, Morio, she sets off for Tokyo to unravel the mystery around her father`s sudden arrest. Along the journey, she soon realises that her recurring dream may be the key to the mystery.