Basara is stunned when his father informs him that he has two step-sisters, who then move in with them. When his father goes on a business trip shortly thereafter, the two girls turn out to be members of a demon clan.

After his official acceptance into their family, Basara and Mio enter into a master-servant magical pact under the watchful eyes of Maria.

Aware that Yuki is watching Mio instead of the hero clan, Basara informs Yuki of Mio's past and says he wants to protect her.

During a fight with the stranger and his cronies, Basara receives an injury which makes Mio lose control of her powers.

After Yahiro's defeat, Basara awakens to find Maria lying on top of him; a group of hero clan member scheme to murder Mio.

Miro shows up in the middle of Basara and Yuki's date in hopes of interfering; when Yuki splits off from the group, a demon called Valga attack Basara, Mio and Maria.