Mage & Demon Queen is set in a fantasy world operating by the rules of role-playing games, where teams of human adventurers seek to challenge the Demon Tower, and whoever can ascend to the top floor and defeat and kill the Demon Queen Velverosa will gain fame and fortune and a rich reward from the kingdom, with near-unlimited retry opportunities thanks to resurrection magic.

A particular thorn in the Demon Queen's side is Malori, a particularly powerful young mage that has repeatedly reached the top at the expense of her best friend Cerik, not to kill her, but to win her hand in marriage.