During winter break, odd occurrences at Reien Girls' Academy prompt Azaka Kokutou—an apprentice mage and student—to investigate on her master"s orders. She discovers another sorcerer has been siphoning students" memories through fairies that, even with her skill, remain unseen by Azaka. Consequently, Shiki Ryougi, an acquaintance possessing special sight that reveals what Azaka cannot perceive, is dispatched to the school to aid in resolving the crisis. The pair initially clash, largely because Azaka regards Shiki as a romantic competitor. Yet when the fairy plot escalates and deeper enigmas surface, Azaka learns to cooperate with Shiki to protect their classmates. Their investigation uncovers hidden wards and an ancient pact, hinting the fairies were guardians; Azaka learns a counter-spell while Shiki traces its source.