Shakugan no Shana

Not long after he enters high school, Sakai Yuji’s normal days come to an end. He's caught in something bizarre on his way home, people around him are frozen in a strange fire, and a large doll is attacking them. Just when he's about to be eaten by the monster, a girl in a dark cloak and blazing red hair wielding a large sword appears, and slices the monster in half. Although Yuji survives the strange encounter with the help of the strange girl, the girl informs him of a desolate truth: "You are already dead."

She calls herself a Flame Haze who hunts “Guze no Tomogara”. She explains to him that he is a "Torch”, a substitute existence for the already dead Yuji Sakai whose “existence” has already been devoured. Though Yuji can't wrap his head around what she has told him he still whants to believe that he is still alive and that it's all just a dream. He tries to befriend the girl and get to know her name but instead she tells him that she has no name and that everyone juust calls her either "The Flaming Red-Haired Blazing-Eyed Hunter" or "She who wields Nietono no Shana". Yuji feels bad for her so he thinks of a name for her and He begins to call her "Shana". She at first dosen't like it but her crimson lord with whom she has made a contract with Alastor takes a liking to her new name, and in time she begins to like the name and everyone just begins to call her Shana.