Three elementary school girls, Sumi Washio, Sonoko Nogi, and Gin Minowa, receive a crucial mission in the year 298 of the god's era. They must transform into heroes to combat the enigmatic Vertex, assailants threatening Shinju-sama, the divine tree safeguarding Shikoku, the sole habitable region remaining. Unaware of the impending toll, these young heroines are about to face sacrifices beyond their wildest expectations.