Mio is a young girl that appears to be in her mid teens. She is the first person Aur meets when he makes advances on the first village after summoning Lilu. Mio is in charge of the livestock on the dungeon and is also given a hell hound to care for. She was originally intended as the blood sacrifice for when Logan was summoned, but was replaced by Mary (as Logan is a Lolicon). Her entire existence was taken up by Aur when they had sex in the bath where she became fully subservient in both body and soul. When Aur was captured, she was one of his rescuers with a pair of Wyverns under her control. Mio is completely devoted to Aur as he is her existence.
She was seen drying clothes, until after Aur suddenly approached her. Aur commanded her to tell the village head about his arrival. Confused, Mio kept silent. Aur, who was pissed off then threatened. Aur demonstrated his abilities by burning up a field behind him. Panicked, she immediately ran away in order to tell the village head. Sometime later, Aur, initially intended sacrificed Mio to form a contract with Logan. However, Logan, who is a lolicon, agreed to form a contract with him upon meeting Marybelle.