In the near future, humanity faces imminent destruction from mysterious creatures known as "Huge." The world wages war against the Huge, and develops the anti-weapon "CHARM" (Counter Huge Arms) by combining science and magic. CHARM works more effectively when used by teenage girls, and those who use the weapons are revered as "Lilies." The Lilies are trained at military academies called "Gardens," which also serve as bases to protect and advise people. This is a story about girls who aim to become Lilies so they can protect Earth.