How a Light Novel Pushed Broadcast TV to Its Limits
The Testament of Sister New Devil has always been a series that dares you to look away — and then hooks you with genuinely solid action writing before you can. Based on the light novel by Uesu Tetsuto (上栖綴人) with illustrations by Ōkuma Nekosuke (大熊猫介), the franchise has now crossed 3.2 million copies in cumulative worldwide sales, a milestone highlighted in a recent TRILL retrospective examining the show's unlikely broadcast TV run.
The premise is deceptively simple. Tōjō Basara's father remarries, and overnight he gains two beautiful stepsisters: Naruse Mio and Naruse Maria. Standard romantic comedy setup — except Mio turns out to be the daughter of a former Demon Lord, and Maria is a succubus. What starts as slapstick quickly escalates into a supernatural battle series with real stakes, and that tonal whiplash became the show's signature.
Produced by Production IMS and directed by Hisashi Saitō, the anime aired its first season on January 7, 2015, followed by a second season titled The Testament of Sister New Devil BURST on October 9, 2015. An OVA, The Testament of Sister New Devil DEPARTURES, rounded out the adaptation. The manga was serialized across two magazines — Monthly Shōnen Ace at KADOKAWA and Young Animal Arashi at Hakusensha — giving the franchise a broad print footprint.
The Episode 1 Bait-and-Switch That Hooked Viewers
The anime's first episode became a talking point the moment it aired. Within minutes, Basara accidentally walks in on Mio in the bathroom — cue heavy white censoring and a hard slap. Maria wakes him up by climbing on top of him. She later appears in the kitchen wearing an apron and not much else. The dialogue leans hard into innuendo even during casual conversation.
Then, midway through the episode, the tone flips entirely. Mio and Maria reveal their true identities and attempt to seize control of the household through a master-servant contract. Basara counters by revealing he's a member of a hero clan, pulling out a massive sword, and shutting the contract down. The shift from ecchi comedy to full-throttle battle action was jarring in the best way — it gave viewers a reason to stick around beyond the fanservice.
Yūichi Nakamura (Satoru Gojo in Jujutsu Kaisen, Hawks in My Hero Academia) voices Basara, with Ayaka Asai as Mio and Kaori Fukuhara as Maria. Nakamura's performance anchors the tonal shifts, moving from exasperated straight-man comedy to intense battle sequences without missing a beat.
'How Did This Air on Broadcast TV?'
The reaction on Japanese social media was immediate and persistent. "How did this get approved for broadcast television?" became the defining viewer response, according to TRILL's report. The series aired on TOKYO MX and Sun TV — real terrestrial broadcast channels, not late-night premium cable. Viewers noted that the show's content pushed well beyond what they expected from a broadcast anime, with scenes that felt closer to OVA-level material.
But the retrospective makes an important point: the risque content was never the whole story. Episode 1's flashback sequences hint at serious backstories for the main cast, and the battle choreography carries genuine weight. The series earned its 3.2 million copies not just through provocative marketing but by delivering a competent action narrative underneath the fanservice.
Looking Ahead
The Testament of Sister New Devil's anime run wrapped up with the DEPARTURES OVA, and no new anime adaptation has been announced. The original light novel series has concluded. For international fans, the anime is available through Crunchyroll in select regions. The light novel has not received an official English print release, though the manga adaptation saw partial English publication.
With 3.2 million copies in circulation and continued social media discussion more than a decade after its broadcast premiere, the franchise remains a notable example of how pushing content boundaries on broadcast TV can pay off — provided there's substance behind the spectacle.