Misaki-chan owns and cares for Nyanpire, a vampire cat she rescued outdoors. She governs his behavior with firm fairness, consistently enforcing rules like limiting his blood intake despite his loud protests, while ensuring he lacks nothing essential. After acquiring a second cat, Chachamaru, from a friend, she divides her attention and affection equally between both. Yet, Nyanpire's irresponsible and playful nature compared to Chachamaru's calmer demeanor leads Misaki-chan to scold him more often.

Visually, Misaki-chan remains anonymous, appearing only through isolated body parts like legs, arms, or the back of her head, reinforcing her role as an unseen caregiver. The narrative later introduces a thematic concern regarding Nyanpire's vampire immortality contrasting with Misaki-chan's human mortality, acknowledging the inevitable reality that he will outlive her and his non-vampire companions, introducing melancholy about their future separation.