The Japanese artist Nekosuke Ookuma published a special illustration to celebrate that September 29, 2022 marked ten years since the release of the first volume of the light novels written by Tetsuto Uesu, Shinmai Maou no Testament (The Testament of Sister New Devil). The visual is starring Mio Naruse and Basara Toujouwho are also protagonists of the original work.

Uesu and Ookuma began publishing the light novels through the publishing label Sneaker Bunko from the publisher Kadokawa in September 2012. The publisher published the twelfth volume in April 2018, and this had been described as the last in the series, but a thirteenth volume was released in March 2021 to definitively conclude the story.
In addition to a manga adaptation by Kashiwa Miyako and other derivative works, the work inspired a twelve-episode anime adaptation produced by the studios Production IMS and premiered in January 2015. A second season of ten episodes with the same production team was released in October 2015, followed by an OVA in March 2018.
Synopsis of Shinmai Maou no Testament
Meeting his new stepsister in the bathroom is not the best way to make a good first impression, which Basara Toujou learns the hard way. When his father suddenly brings home two beautiful girls and introduces them as his new sisters, he has no choice but to accept the Naruse sisters into his family: busty redhead Mio and little silver-haired Maria. But when these seemingly normal girls reveal themselves to be demons, Mio the only daughter of the former Demon Lord and Maria his trusted succubus servant, Basara is forced to reveal himself as a former member of a clan of “Heroes,” sworn enemies of demons.
However, having begun to worry about his new sisters, Basara decides to protect them with his powers and forms a master-servant contract with Mio to keep an eye on her. With the Heroes watching his every move and the constant threat of hostile demons, Basara has to go above and beyond to protect his new family members. Furthermore, the protector himself hides his own dark secret that still haunts him to this day…
Fountain: Official Twitter Account
© 上栖綴人 (著), 大熊猫介 (イラスト) / KADOKAWA
