On this world, humans are invaded by the existence called Yuugenshu. People were able to survive because of the floating continent, Obie Crea, protected by Priestesses’ prayers.
Sheltis had once aimed to become a Sen'nenshi—a partner of Yumii, his childhood friend and also a Priestess. However, because he fell from the continent to the Eden , he harbored Mateki, what only…