In a ruined future Nerima, a photon energy disaster is said to have devastated the area. No one knows whether that is true or not, and details are hard to come by. All that is left is the photon research facility tower that stands as a monument at the center of the devastation. Z-chan and Gre-chan live together in the Shutter District, which spreads from the base of the tower. Their home is made from salvaged materia...