Yuuji Sakai's high school life has just begun, but his ordinary life that was supposed to continue has changed dramatically because of an accident. On the way home, the time and space of the shopping street suddenly stopped, and the souls of all people in this closed space were sucked away by monsters. The beautiful red-haired girl holding a Japanese sword and fighting monsters told Yuuji the shocking truth: "You are dead, and now you are just living in another form." Yuuji accepted this fact and decided to fight for the world with this beautiful red-haired girl, and called her "Shana" after the girl's weapon. For the future of the world, Shana was involved in battles again and again, and the bond between the two began.