Rei: a normal high school student living in a world of monsters
Atkirkne: a K-xyouix (Kay-shoe) pretending to be Tsukamoto Ayaka, a cute high school girl.
This story of the sky takes place in what used to be Tokyo, Japan. Ever since the great catastrophe, everything and everyone has changed. Japan was taken over by the K-xyouix, an alien race that created a floating world for mysterious beings. Meanwhile, the ground has become a war zone with barely any hope left.