TV series
Toujou Basara is a high school student whose father has suddenly just remarried. His father then departs overseas leaving Basara with two new beautiful step-sisters. Little does he know, his new sisters, Mio and Maria are actually the new Demon Lord and a succubus!? Almost trapped into a life of servitude, Basara forms a reverse contract by accident and ends up becoming Mio's master! Hijinks ensue as Basara finds himself in one ecchi situation after another. However, Mio's life is in danger as she is pursued by demons and heroes!
Streaming, rental and purchase options
Checked Jul 22, 2026
The Testament of Sister New Devil is available to stream on Crunchyroll Premium (Via Amazon Prime) in United States. You can also buy it from Apple TV. Use the direct links below to open the provider.
Toujou Basara is a high school student whose father has suddenly just remarried. His father then departs overseas leaving Basara with two new beautiful step-sisters. Little does he know, his new sisters, Mio and Maria are actually the new Demon Lord and a succubus!? Almost trapped into a life of servitude, Basara forms a reverse contract by accident and ends up becoming Mio's master! Hijinks ensue as Basara finds himself in one ecchi situation after another. However, Mio's life is in danger as she is pursued by demons and heroes!
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Episode 1
Thanks to his father's sudden remarriage, Toujou Basara finds himself with two beautiful new step-sisters. Their names are Naruse Mio and Maria. Mio wakes him up in the morning, while Maria stands in the kitchen wearing a suggestive outfit...
Directed by Tatsuma MinamikawaGuest stars Keiji Fujiwara, Hiroki Etou, Masaaki Itatori, Masaaki Yano, Shuusaku Shirakawa, Reina Kimura
Episode 2
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.
Directed by Kiyomitsu SatoGuest stars Tomokazu Sugita, Sarah Emi Bridcutt, Saeko Zogo, Misato, Kenjiro Tsuda
Episode 3
Basara's childhood friend Nonaka Yuuki warns him not to get involved with Naruse Mio any longer. She is a fellow member of the hero clan, and the one charged with observing Mio. She claims that Mio will bring great disaster, but Basara proclaims that he will protect Mio as a girl on his own.
Directed by Takashi AndoGuest stars Tomokazu Sugita, Yuu Asakawa, Sarah Emi Bridcutt, Natsumi Oshita, Masaaki Yano, Tomokazu Sugita, Reina Kimura
Episode 4
Basara suffers a deep wound in the battle against the white-masked man after Mio's power. Mio regrets getting Basara involved, and challenges the white-masked man to battle on her own. Meanwhile, in order to protect Mio, Basara resolves to use the "forbbiden art" he sealed away after the events of his past. What was the tragedy that visited the hero village and Basara?
Directed by Naoya AndoGuest stars Tomokazu Sugita, Sarah Emi Bridcutt, Keiji Fujiwara, Hiroki Etou, Masaaki Itatori, Osamu Kaneko, Masaaki Yano, Rika Kinugawa
Episode 5
With the battle against the white-masked man settled, they returned to their bawdy daily life. Basara wakes up with his hand groping Maria's butt, he runs into a naked Mio when he enters the bathroom, and Yuki sneaks into the bath with him. The master-servant pact lying at the heart of everything. Accoring to Takigawa, his classmate and the white-masked man, the pact between Basara and Mio holds another secret. Meanwhile, Basara's childhood friend Yuki invites him out on a date...
Directed by Shinsuke YanagiGuest stars Tomokazu Sugita, Yuu Asakawa, Iori Nomizu, Sarah Emi Bridcutt, Seiko Yoshida, Masaaki Yano, Reina Kimura, Kenji Nomura
Episode 6
Basara goes on a date with Yuki. Unaccustomed to the shopping center, when the two of them are overwhelmed by a clerk's sales talk, Mio stops following to rescue them.
Directed by Yoshito MikamoGuest stars Tomokazu Sugita, Iori Nomizu, Sarah Emi Bridcutt, Keiji Fujiwara, Kenji Nomura, Daisuke Hirakawa, Go Inoue, Misuzu Togashi
Episode 7
Basara leads Mio to higher peaks as he pursues pleasure with the use of syrup. With their master-servant pact reaching a new level, they both bring their full might to face the ones trying to eliminate Mio: Takashi and Kurumi.
Directed by Takashi AndoGuest stars Iori Nomizu, Sarah Emi Bridcutt, Daisuke Hirakawa, Go Inoue, Masaaki Itatori, Misuzu Togashi, Chiharu Kitaoka
Episode 8
Ten days pass since the battle with Takashi and others. Although the battle ended with reconciliation, Yuki returned to the hero's village. ...or she was supposed to, but when Basara returns home, he finds Yuki in an apron!
Directed by Yoko FukushimaGuest stars Tomokazu Sugita, Sarah Emi Bridcutt, Keiji Fujiwara, Seiko Yoshida, Yukiko Aruga, Hiroki Etou, Masaaki Yano, Reina Kimura
Episode 9
Basara and Yuki begin the ceremony to form their pact. Clad in a bustier and garter belt, Yuki was raring to go for it, but she refused to forge the pact normally, and suffered the same succubus curse as Mio.
Directed by Koji YoshikawaGuest stars Tomokazu Sugita, Yuu Asakawa, Sarah Emi Bridcutt, Seiko Yoshida, Mina, Masaaki Itatori, Hiroto Kazuki, Saeko Zogo
Episode 10
Mio has been captured by Zolgia following Maria's betrayal. Basara too is captured by Lars and brought to Zolgia's mansion. Lars' goal is to exchange Basara for Mio. He explains that he's only doing his duty as Mio's observer, but negotiations fail, and Zest slays him.
Directed by Yu SakuraiGuest stars Sarah Emi Bridcutt, Seiko Yoshida, Hiroto Kazuki, Tomokazu Sugita
Episode 11
Strength as a human, the power to rend evil--With the power inherited from his father, Tojou Jin, Basara faces off against Zolgia. Basara is driven by the desire to protect his precious family. That desire gives him strength, and even as Zolgia pushes him to the edge, he rises without breaking. However, even Basara eventually runs out of strength facting that all too powerful might. His mind in despair, he's unable to escape from Zolgia's dominion...
Directed by Yushi SuzukiGuest stars Yuu Asakawa, Iori Nomizu, Sarah Emi Bridcutt, Keiji Fujiwara, Seiko Yoshida, Hiroto Kazuki, Tomokazu Sugita, Kumiko Nishihara
Episode 12
Everyone is trapped inside the body of the demon realm's most dangerous creature, a beast capable of infinitely multiplying until it swallows the entire world. Dimensionally cut off, the only remaining option for Basara and the others is to completely eliminate this dangerous creature's vital core.
Directed by Yushi SuzukiGuest stars Sarah Emi Bridcutt, Keiji Fujiwara, Seiko Yoshida, Hiroto Kazuki, Hiroki Etou, Keiichi Nakagawa, Tomokazu Sugita, Kazuyuki Okitsu
Episode information updated Jul 23, 2026
Yuichi NakamuraBasara Tojo (voice)
Ayaka AsaiMio Naruse (voice)
Kaori FukuharaMaria Naruse (voice)
Yuu AsakawaChisato Hasegawa (voice)
Iori NomizuKurumi Nonaka (voice)
Sarah Emi BridcuttYuki Nonaka (voice)
Keiji FujiwaraJin Tojo (voice)
Seiko YoshidaZest (voice)
Tokyo MXJapan
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