Mio Naruse

Mio Naruse is the main female protagonist of the series. She is the daughter of the previous Demon Lord, Wilbert and a human named Ashe thus making her a humanoid demon, as well as the niece of Sapphire. After the "death" of her father, Mio inherited his power and was raised in the Human World as the daughter of two unnamed demons as a human. Though after the death of her adoptive parents, she was later saved by Maria who revealed the truth about her lineage. Both later came up with the ruse where their "mother" would be marrying Jin Toujou and become the stepsisters of Basara in an attempt to make their house their base, while father and son would have their memories altered and move elsewhere. However, this plan failed after both of them were revealed to be banished members of the Hero Clan, but Mio and Maria continue to live in the Toujou Household. Mio is a beautiful young woman shorter than Basara with long crimson hair reaching her waist and pink eyes. For someone her age, she has been noted for having a distinctly slender yet curvaceous figure with enormous, bouncy breasts and sizeable buttocks. Most of the time, she is seen dressed in the uniform of her school, which resembles a white sailor uniform that has a black collar and black cuffs that has white horizontal stripes, an orange-colored tie hanged from the edges of her collar, a short black skirt that has a single white stripe, long black socks that has a red-colored ribbon around her upper thigh, and a pair of maroon-colored shoes. Because of the constant Master-Servant Contract, and then the Vow, Mio's has become more seductive and sexy, something that most humans have noticed too, her breasts have started growing more too. Mio is shown to be a calm and quiet person, especially around those she isn't close to, but she's rather talkative around her closest friends such as Chika and Shiho. It is noted that she can be rather quick to anger based on the situation, mostly if someone close to her is threatened, insulted or harmed, first shown when she slapped Takashi who didn't understand it was Basara who was suffering more than anyone after the incident from six years prior. Mio can also become enraged if she believes someone important to her has been killed to the point of wanting to eliminate the person responsible herself. Despite being referred to as a dangerous threat by the Hero Clan, Mio is rather caring, honest and compassionate. She hates lying for the most part to those who have helped her as shown when she and Maria lied to Basara and Jin about their marriage to use their home as a base, even choosing to erase their memories so they wouldn't get involved in their problems anymore. Although Mio attempts to act brave and calm all the most, deep down she is afraid about her current situation since she has lived most of her life as a normal high school girl; however, when faced with danger she won't hesitate to face the challenge. She soon becomes rather close to both Basara and Jin, who she views as being her family. Mio is more close to Basara who she has shown to have some hidden feeling for, but she acts in a more tsundere manner when it is brought up, but Mio's true feelings sometimes comes out when under the effect of the Master-Servant Contract and she refers to him as "Onii-chan" whenever he does anything perverted to her. She becomes rather jealous when he does anything with other girls such as Yuki and Maria, albeit the former is the result of accidents and the latter being due to the succubus' antics. Due to their constant interactions, she becomes more open about her feelings with Basara reaching the Master-Servant Vow and surrendering herself to him completely. She appeared to dislike perverts as noted in her initial interaction with Basara who walked in the bathroom when she was in there, albeit their lock wasn't fixed. Mio is also prone to sudden outbursts when faced with inappropriate situations such as finding erotic magazines under Basara's bed (despite Mio herself being on top of him in an erotic position while he slept) or being left at the mercy of Maria's succubus curse. As she continued to be affected by the Master-Servant Pact, Mio has become more open with her own desires to where she doesn't mind doing things with Basara and the other girls.