Momiji Fujimiya, is a descendant of the mythical Princess Kushinada. When Japan is menaced by Aragami spawned by Yamato-no-Orochi, Momiji is intended to be sacrificed to appease the Aragami. She instead, however, becomes a member of the Terrestrial Administration Center, a secret agency charged with fighting them.
The series centers on Momiji Fujimiya, a seemingly average Japanese middle school student from Izumo. Her life is suddenly upended when she discovers she is the last living descendant of the mythical Princess Kushinada, whose special blood holds the power to defeat the Aragami. The Aragami are monstrous, plant-like creatures that manifest in Japan, seeking to destroy humanity. Momiji's destiny, according to ancient tradition, is to be a human sacrifice to appease or defeat these creatures, an idea she strongly rejects.