Aura: Koga Maryuin's Last War

Satou Ichirou once called himself 'Maryuuin Kouga' and behaved as if he were a hero in a fantasy world. His strange behavior caused his classmates to bully him and he left the school. At his new school, he tries to behave like a normal boy, but one day he meets a girl who cosplays with a blue cape. She calls herself "a researcher traveling from the outer world to search for the 'Dragon Terminal'".