Chivalry of a Failed Knight

The "school sword action" story revolves around Magic Knights, modern magic-users who fight with weapons converted from their souls. Ikki Kurogane goes to a school for these Magic Knights, but he is the "Failed Knight" or "Worst One" who is failing because he has no magical skills. However, one day, he is challenged to a duel by Stella, a foreign princess and the "Number One" student. In this duel, "the loser must be obedient for life." (Source: Anime News Network)

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)