Haneru Tobitatsu, a dance-loving middle schooler, secretly practices his moves by the mirrored window of an old building, unaware that a girl named Kanon Otosaki is watching from the other side. When Haneru later hears about an online dancer known as Rhythm, he decides to try out his moves at the building again. When the passing time causes the window to become see through, Haneru sees Kanon, who was using the building to shoot videos as Rhythm, dancing alongside him, showing an immediate interest in teaming up with her.