and also cleansing the area of the evil spirit. Yuki is spared and the cursed sword Brynhildr is cleansed. Because of this, he is confined in the village and when Basara's father returns he insists that Basara be released, which he is, but only on the condition that Jin lose his title as a hero. Jin chooses the release of his son and they move to the city. In the present, Basara's father tells him that he is remarrying and that Basara is going to have two younger stepsisters, Mio and Maria. The four of them move into a new house (since the girls' mother is away overseas) and Jin is soon called away on business. The girls take advantage and try to force Basara to leave the house using magic. However, this backfires and Basara tells them to leave. He then contacts his father who reveals the girls' true nature to Basara and why he took them in. Having decided to protect them as their older brother, and in spite of their deception, Basara goes after the girls and saves Mio's life. Maria has Basara and Mio perform a master–slave magical contract that allows them to know each other's location. But, Maria unexpectedly makes Basara the master and Mio the slave, not the other way around and because Maria used Succubus magic to form the contract, the penalty for a disloyal servant is a strong aphrodisiac effect that can only be relieved by the touch of the master, leading to a strong orgasmic release. He has also entered a pact with Yuki in order to boost their fighting strength. Mio, the titular heroine, is a Demon princess and heir of the former Demon Lord, Wilbert, as well as niece to the current Moderate Faction leader, Ramsus. She grows up in the care of some of Wilbert's followers ignorant of her heritage. Mio becomes aware of her heritage and inherits her true father's abilities after his death only six months before meeting the Tojo family. She and Maria are hiding from the current Demon Lord Leoheart's minions who want to kill her for the powers that she inherited. This is the reason why Jin Tojo takes Mio and her succubus retainer, Maria, in to protect them and prevent the current Demon Lord from becoming stronger. Mio is not pleased with the results of Maria's bonding spell, but she eventually develops