"Chanto Suenai Kyūketsuki-chan" centers on a young vampire girl named Sophie Twilight, who lives a quiet, nocturnal life in modern-day Japan. Unlike traditional vampires, Sophie is not malevolent or bloodthirsty; she prefers to live peacefully and orders blood packs online to sustain herself. Her daily routine is disrupted when she encounters a series of supernatural and human characters who bring chaos into her otherwise orderly existence. Among these characters is Akari Amano, a human girl who becomes fascinated with Sophie and insists on becoming her friend despite Sophie's initial reluctance. Akari's energetic and intrusive nature often clashes with Sophie's reserved and introverted personality, creating a dynamic that drives much of the series' humor and lighthearted moments.

The narrative explores Sophie's interactions with other supernatural beings, including a half-vampire named Ellie, who is more aggressive and traditional in her approach to vampirism, and a werewolf named Haruka, who is fiercely protective of her territory. These characters frequently cross paths with Sophie, leading to comedic misunderstandings and occasional conflicts. The series balances slice-of-life elements with supernatural themes, focusing on Sophie's attempts to maintain her peaceful lifestyle while navigating the eccentricities of those around her. The episodic structure highlights her struggles with modern technology, her efforts to avoid drawing attention to her vampiric nature, and her gradual acceptance of the friendships that form despite her initial resistance. The tone remains light and comedic, with occasional moments of introspection about identity and belonging.