After a year at boarding school, Shion Sonozaki flees the oppressive institution and secretly returns to her hometown in the mountains, telling only her twin sister Mion of her arrival. Though the Sonozaki family has kept the sisters apart to prevent conflict over who would become the next family head, Mion and Shion have remained close - enough so that Shion can easily impersonate her identical twin. When Shion encounters Satoshi Hojo in town, he is completely taken in by her 'Mion' disguise. And Shion is quite taken with him... But on the night of the Cotton Drifting Festival, Satoshi's abusive aunt is brutally murdered. Unable to provide an alibi for the night of the festival, Satoshi becomes the prime suspect for the murder of his aunt! As her friend is hauled away by the police, Shion steps forward as a witness to Satoshi's whereabouts that night, exposing her true identity in the process. Shion may have saved Satoshi this time but her actions have put her in serious danger. What will the Sonozaki family do to Shion when they learn of her association with Satoshi Hojo? And what will they do to Satoshi?