"Is This a Zombie?" is a supernatural comedy anime that blends elements of fantasy, action, and harem genres. The story centers on Aikawa Ayumu, a high school student who is murdered by a serial killer but is resurrected as a zombie by the necromancer Eucliwood Hellscythe. Ayumu retains his human appearance and consciousness but gains the ability to regenerate from injuries, though he remains undead. His life takes a bizarre turn when he encounters a magical girl named Haruna, who mistakes him for a fellow magical girl and accidentally transfers her powers to him. As a result, Ayumu is forced to fight monstrous beings called Megalo while dressed in a frilly magical girl outfit, adding a layer of absurdity to his already unusual existence.

The narrative expands as Ayumu becomes entangled with other supernatural beings. Haruna, a self-proclaimed magical girl, is actually a masou shoujo, a warrior who battles Megalo using a chainsaw-like weapon. Seraphim, a vampire ninja, also enters Ayumu's life, seeking to protect him due to her own mysterious connection to Eucliwood. Meanwhile, Eucliwood, a powerful and enigmatic necromancer, communicates through written notes due to her overwhelming magical abilities, which can cause catastrophic events if she speaks. The group is further joined by Tomonori, a perverted and eccentric vampire ninja who adds to the chaotic dynamics of the cast.

The plot unfolds through a series of episodic adventures, often balancing comedic moments with darker undertones. Ayumu's interactions with the eccentric cast reveal their individual backstories and motivations, such as Eucliwood's tragic past and Haruna's insecurities about her role as a masou shoujo. The series explores themes of identity, friendship, and the consequences of wielding power, all while maintaining a lighthearted tone through its over-the-top humor and absurd situations. The blend of supernatural battles, romantic tension, and comedic misunderstandings creates a unique narrative that keeps the story engaging and unpredictable.