"Petshop of Horrors" is a four-episode anime series based on the manga by Matsuri Akino. The story is set in Chinatown, Los Angeles, and revolves around Count D, the enigmatic proprietor of a mysterious pet shop. The shop specializes in selling rare and exotic animals to customers who must agree to a strict contract. Each episode presents a self-contained story, focusing on a different customer and the consequences of their purchase.

Count D, a pale and androgynous figure with a calm demeanor, offers his clients animals that seem to fulfill their deepest desires or address their personal struggles. However, these creatures often come with unforeseen and supernatural consequences. The contracts signed by the customers include specific rules, and violating these terms leads to dire outcomes, often reflecting the buyer's flaws or hidden sins. The pets, while appearing ordinary, possess otherworldly traits that blur the line between reality and fantasy.

The series also features Detective Leon Orcot, a brash and skeptical police officer who becomes suspicious of Count D after a series of bizarre incidents linked to the pet shop. Leon frequently visits the shop to investigate, often clashing with Count D's cryptic and evasive nature. Despite his skepticism, Leon is drawn into the strange occurrences surrounding the shop and its proprietor. His interactions with Count D reveal glimpses of the latter's mysterious background and the true nature of the pets he sells.

Each episode explores themes of human desire, morality, and the consequences of one's actions. The first episode introduces a man who purchases a rabbit to win the affection of a woman, only to face tragic repercussions. The second episode follows a struggling actress who buys a bird said to bring fame, but at a steep cost. The third episode centers on a young boy who acquires a dragon-like creature, leading to a confrontation with his abusive father. The final episode delves into Leon's backstory and his growing connection to Count D, hinting at a deeper mystery surrounding the pet shop and its owner.

The narrative is driven by a blend of horror, fantasy, and psychological drama, with each story serving as a cautionary tale about the dangers of unchecked ambition and desire. Count D's role as a neutral yet ominous figure adds an air of intrigue, while Leon's grounded perspective provides a counterbalance to the surreal events. The series concludes with an open-ended tone, leaving the true nature of Count D and his shop unresolved, inviting interpretation and speculation.