First Contract Between Servant and Master
As daughter of the former demon lord, Mio's foster parents were slain by powerful demons after her life. Still seeking to slay her, Basara reveals himself as a member of the hero clan--an enemy of the demons--and vows to protect Mio as a member of his family.
Aired 15/01/2015EP 2 - First Contract Between Servant and Master
The Testament of Sister New Devil
When a pair of sexy girls, Maria and Mio, come to live with high school student Basara Toujou, his life changes forever. The two girls have a secret that they don’t keep for long—Maria is a succubus, and Mio is a future Demon Lord. But Basara has a secret of his own—he’s the last descendant from a clan of demon-fighting heroes. To make things even more complicated, the girls force Basara into a master-servant contract, and Basara ends up becoming their master! What happens when you put a succubus, a demoness, and a demon-fighting hero under the same roof? They form a bond that will help them to take on anything!
(Source: Funimation)