Asa Mitaka (三み鷹たか アサ Mitaka Asa) is the main protagonist of the Academy Saga. She is a high school student who became the host of the War Devil, Yoru, making her the inhabitance of the War Fiend (戦せん争そうの魔ま人じん Sensō no Majin), though she still retains her human personality when Yoru allows her control, making her a rare case of a living Fiend host. She attends Fourth East High School with Denji, with whom she briefly attempted to start a relationship, ending in disaster.