Mio Naruse | The Testament of Sister New Devil

“Mm… Ahh, Yah…Don't, Broth- Brother, stop it… I'll kill you a hundred times!"

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 to have very large breasts and a distinctly slender yet curvaceous figure.

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 have a red-colored ribbon around her upper thighs, 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 also grown larger.

Personality:

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.

(...)

I remember watching this anime during my earlier days as an anime fan and the stuff in it was definitely mindblowing. I thought the stuff in Highschool DxD would be the peak but I was mistake