is a Japanese light novel series written by Tetsuto Uesu and illustrated by Nekosuke Ōkuma. Thirteen volumes have been published by Kadokawa Shoten since 2012 under their Kadokawa Sneaker Bunko imprint. A manga adaptation has been serialized in Kadokawa Shoten's Shōnen Ace magazine since May 2013. A second manga adaptation has been serialized in Hakusensha's Young Animal Arashi magazine since February 2014. The first season of an anime television adaptation premiered on January 7, 2015. The first OVA episode was released on June 22, 2015. The second anime television season premiered on October 9, 2015. A second OVA episode was released on January 26, 2016. A third OVA episode was released on March 28, 2018. Plot Basara Tojo is a high school student studying at Hijirigasaka Academy when his father Jin suddenly gets "remarried" and asks Basara if he wants to have sisters. Basara meets his two new, cute stepsisters, Mio Naruse and Maria Naruse. After his father departs overseas, Basara quickly finds that the two sisters are actually part of a demon clan, and he is meant to be with the hero clan. Mio, a Demon princess, forcibly attempts to make a master and servant contract with Basara, but Maria has it end up being the opposite, with Basara as the master. Basara then keeps getting into ecchi scenarios, largely to protect Mio from being pursued by other demons who are after her heritage, which is passed down from the former Demon Lord Wilbert. Characters Main Basara Tojo is a Year 1 high school student at Hijirigasaka Academy and the protagonist of the story. As a member of a hero clan, he grows up in a hidden rural village. Basara wields the formerly cursed sword Brynhildr. Basara is the only son of Jin Tojo, formerly acknowledged to be the 'Strongest Hero' in the village. As Jin's son, great things are expected of Basara and he is unusually strong even as a youth. Basara possesses the skill 'Banishing Shift', which nullifies any skill directed against him. Five years earlier, when Jin is on a trip, the seal of the S-Ranked 'Evil Spirit' is broken. Many people, including his friends and family, are killed by the spirit. When he sees the Evil Spirit trying to harm his childhood friend, Yuki, his Banishing Shift goes out of control, causing a great crater to form, obliterating the bodies of those slain except Yuki,