Mio Naruse is a central character in the anime series "Shinmai Maou no Testament." She is the daughter of the previous Demon Lord, Wilbert, making her the rightful heir to the Demon Lord's throne. Despite her noble lineage, Mio initially lives a normal life until she is thrust into a world of supernatural conflicts. As a high school student, she is strong-willed and determined, often facing adversities head-on. Throughout the series, Mio forms a deep bond with the protagonist, Basara Toujou, and together they navigate the dangers posed by various factions interested in her power.