The 15-year-old Sakai Yūji used to be a normal student, but one day that normal life ended, when he was assaulted by a monster, Guze no Tomogara, from another world that turns humans into edible light. Luckily Yūji was saved by Enpatsu Shakugan no Uchite, a girl with burning hair and red eyes. Though when she tells him, "You don't exist any more.", Yūji knows that his normal life has ended...