Mito Aoi is a high school student living at a shrine with her childhood friend Sousuke. While cleaning the storehouse one afternoon, she finds a silver mirror among the antiques. A thunder strike later, Aoi is absorbed into the mirror and wakes up in 1873 Meiji-era Japan. She encounters a traveling performance troupe called Aoiza and is startled to find a man who looks exactly like Sousuke — who introduces himself as Kaminari Kensuke and denies any resemblance. The troupe keeps calling her by an unfamiliar name. At their headquarters in Ueno she learns that "Futaba Aoi" is a sacred magical stone the group has been protecting for generations — and that it has apparently been living on her wrist her entire life.