"Servamp" is a supernatural anime series that revolves around the interactions between humans and vampires, known as Servamps, who are bound to their masters, or Eve, through contracts. The story begins with Mahiru Shirota, a high school student who values simplicity and avoids unnecessary complications. One day, he encounters a stray black cat, which he names Kuro. Unbeknownst to Mahiru, Kuro is actually a Servamp named Sleepy Ash, one of the seven powerful vampire siblings created by the original vampire, Tsubaki.

Mahiru accidentally forms a contract with Kuro when he gives him a name, binding them together. This contract grants Mahiru the ability to summon Kuro in his human form, a laid-back and apathetic vampire with immense power. As their bond deepens, Mahiru learns about the existence of other Servamps and their Eves, each representing one of the seven deadly sins. The series explores the dynamics between these pairs, as well as the conflicts that arise from their differing goals and personalities.

The central conflict emerges when Tsubaki, the first Servamp and embodiment of the sin of melancholy, seeks to destroy humanity and the other Servamps. Tsubaki's plan involves manipulating the relationships between the Servamps and their Eves, exploiting their weaknesses and insecurities. Mahiru and Kuro, along with other Servamp-Eve pairs, are drawn into this conflict, forcing them to confront their own fears and desires while navigating the complexities of their bonds.

Key characters include Mahiru Shirota, the pragmatic and kind-hearted protagonist; Kuro (Sleepy Ash), the lazy yet powerful Servamp; Tsubaki, the antagonistic first Servamp; and other Servamp-Eve pairs such as Lawless (Lust) and Hyde (Jealousy), each embodying their respective sins. The narrative delves into themes of trust, loyalty, and the consequences of power, as the characters grapple with their roles in the unfolding battle between Servamps and humanity.

The series balances action, humor, and emotional depth, with a focus on the evolving relationships between the characters. As the story progresses, alliances are tested, secrets are revealed, and the true nature of the Servamps' existence comes to light. The interplay between the characters' personal struggles and the larger conflict drives the narrative forward, culminating in a climactic confrontation that challenges their beliefs and resolves their fates.