The Testament of Sister New Devil

The Testament of Sister New Devil is a TV anime adaptation of the light novel series by Tetsuto Uesu, blending action, fantasy, romance, and ecchi into one thrilling package. When Basara Toujou suddenly finds himself with two new stepsisters—Mio Naruse and Maria Naruse—he's dragged into an epic conflict between gods and demons. Alongside fierce allies like Yuki Nonaka, the story delivers non-stop excitement and compelling character dynamics. Produced by Production IMS, directed by Hisashi Saito, and with series composition by Takao Yoshioka, this anime brings the beloved source material to life with style. A must-watch for fans of fantasy harem adventures.

Set in a world where humans and demons exist in an uneasy balance of hidden power struggles, The Testament of Sister New Devil follows Basara Toujou, an ordinary-looking high school student who carries an extraordinary legacy—he is the last heir of a legendary clan of heroes sworn to combat demonic forces. His seemingly quiet life is upended when two alluring girls, Maria Naruse and Mio Naruse, suddenly move into his home as his new stepsisters. What appears to be a typical domestic arrangement quickly reveals itself to be anything but ordinary. Mio holds a position of great significance within the demon world, while Maria is a succubus with her own agenda. Thrown together under one roof, a hero's descendant and two girls from the demon realm find themselves entangled in a web of secrets, supernatural politics, and unexpected bonds—setting the stage for a story that will shake both the human and demon worlds alike.