Running into your 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 siblings, he has no choice but to accept into his family the Naruse sisters: busty redhead Mio and petite silver-haired Maria.
But when these seemingly normal girls reveal themselves as demons—Mio the former Demon Lord's only daughter and Maria her trusted succubus servant—Basara is forced to reveal himself as a former member of a clan of "Heroes," sworn enemies of the demons. However, having begun to care for his new sisters, Basara instead decides to protect them with his powers and forms a master-servant contract with Mio to keep watch over her.
With the Heroes observing his every move and the constant threat of hostile demons, Basara has to do the impossible to protect his new family members. Moreover, the protector himself is hiding his own dark secret that still haunts him to this day...
The Testament of Sister New Devil has finished airing and it has 12 Episodes. It is also Known as: 新妹魔王の契約者〈テスタメント〉, Shinmai Maou no Keiyakusha
Genres: Slapstick , Violent Retribution For Accidental Infringement , Stereotypes , Action , Fantasy , Comedy , Ecchi , Romance , Harem , Parental Abandonment , Demon
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Top Anime Like The Testament of Sister New Devil (Shinmai Maou no Testament) [2026 List]
3. C³
From the light novel series written by Minase Hazuki, comes a story of love, action, and comedy. Yachi Haruaki is a high school boy who is naturally resistant to curses. After his father sends him a mysterious black cube, Haruaki awakes to find a nude girl named Fear standing in his kitchen. She’s the human form of the cursed black cube – and an instrument of torture! Utilizing her special abilities, Fear fights alongside Haruaki to defeat other cursed instruments and their owners.
C³ - CubexCursedxCurious has finished airing and it has 12 Episodes. It is also Known as: シーキューブ, C3, C Cube, C^3
2. Shinmai Maou no Testament Burst
It's hard being the older step brother to a pair of demonic sisters. It's even harder having to defend them from the power hungry denizens of the demonic underworld. Such is the life of Basara Toujou; and he's done a pretty decent job of managing it so far. Shinmai Maou no Testament Burst directly follows the events of the previous season, with Basara and his sisters Mio and Maria Naruse attempting to enjoy a somewhat normal life. The best laid plans of demons and men oft go awry however, and Basara, Mio, and their friends begin to face a number of new threats.
As if the situation couldn't get complicated enough, Maria's older sister Rukia shows up, insisting that Basara and the Naruse sisters must come to the realm of demons.
The Testament of Sister New Devil: Burst has finished airing and it has 10 Episodes. It is also Known as: 新妹魔王の契約者 BURST, The Testament of Sister New Devil: Burst
1. Shinmai Maou no Testament
Running into your 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 siblings, he has no choice but to accept into his family the Naruse sisters: busty redhead Mio and petite silver-haired Maria.
But when these seemingly normal girls reveal themselves as demons—Mio the former Demon Lord's only daughter and Maria her trusted succubus servant—Basara is forced to reveal himself as a former member of a clan of "Heroes," sworn enemies of the demons. However, having begun to care for his new sisters, Basara instead decides to protect them with his powers and forms a master-servant contract with Mio to keep watch over her.
With the Heroes observing his every move and the constant threat of hostile demons, Basara has to do the impossible to protect his new family members. Moreover, the protector himself is hiding his own dark secret that still haunts him to this day...
The Testament of Sister New Devil has finished airing and it has 12 Episodes. It is also Known as: 新妹魔王の契約者〈テスタメント〉, Shinmai Maou no Keiyakusha
