the story largely takes place in misaki city in japan and begins when high school student yuji sakai is thrown into the middle of this conflict and encounters a flame haze girl with flaming red eyes and hair dressed in all black wielding a katana. the girl informs him that he died some time ago, and that he is a , a human with greatly diminished power of existence, and whose remaining power of existence will slowly run out. in addition, yuji is a , a special kind of torch who contains a , a magical object created by denizens that can provide special abilities or even powers of unrestraint; additionally, mystes can move within seals. unfazed by his apparent death, yuji befriends the girl and names her "shana" after her sword. they later discover that the treasure tool within yuji is the , which restores his power of existence every night at midnight.