The story centers on the characters Maō (Demon Queen) and Yūsha (Hero) who live in a world where humans and demons are at war. Yūsha confronts Maō about the destructive war that the demons have imposed on humans. However, Maō tells him that the war has created a reason for humans to work together and improved human society overall. She convinces him that humans would fall into a bloody civil war without their battles against the demons. To prevent such a conflict, Yūsha decides to join forces with Maō.