On Earth in the near future, mankind was on the verge of destruction from an attack by a mysterious life form called the Huge. The whole world united together against this threat, using magic and science to create weapons called Charms. Around the world institutions known as Gardens raise girls called Lilies to wield these weapons. Riri Hitotsuyanagi managed to pass the exam to enter the prestigious Garden known as Yurigaoka Girls' School. She entered in an attempt to find Yuyu Shirai, a girl who rescued her in her past.