The Testament of Sister New Devil

The Testament of Sister New Devil was produced by Studio IMS and premiered in 2015, based on the light novel series written by Tetsuto Uesu. The adaptation emerged during a period in the mid-2010s characterized by the proliferation of ecchi-themed fantasy anime, aiming to capitalize on the popularity of high-stakes supernatural battle series intertwined with fan service elements. It tells the story of a high school student who unexpectedly gains a demon sister and a succubus as stepsisters, thrusting him into a complex web of infernal politics and combat.

The character designs for the anime were handled by Yoshihiro Watanabe, who sought to translate the intricate, suggestive aesthetic of the original illustrations into a format suitable for television broadcast. Upon its release, the series was received primarily as a quintessential example of its genre, noted by critics for its focus on mature themes and action sequences. Its visual direction and narrative structure reflect the common production tropes of that era's studio output, balancing character-driven drama with the heightened, sensationalist pacing expected by its target demographic.