Somewhere in the vast reaches of the internet, a rumor persists about a mysterious website called the Jigoku Tsushin, or Hell Correspondence. Accessible only at the stroke of midnight, the site allows a person consumed by hatred to type in the name of their tormentor. If they do, the Jigoku Shoujo, the Hell Girl, will appear before them. This girl, Ai Enma, offers the client a small straw doll with a red string tied around its neck. She explains the contract: if the client pulls the string, she will immediately ferry the object of their hatred straight to hell. However, there is a price. In exchange for this revenge, a black crest appears on the client's chest, and upon their own death, their soul will also be condemned to hell.

The 2006 live-action television series, which aired for 12 episodes on Nippon Television, brings this supernatural premise to a modern Japanese setting, blending horror, drama, and thriller elements. Each episode functions as a self-contained story, following a different client as they suffer escalating torment from a bully, a colleague, a family member, or another antagonist. Driven to despair, the client accesses the Hell Correspondence, debates the moral and eternal cost of revenge, and ultimately decides whether to pull the string. If they do, Ai Enma and her three assistants—the composed young man Ichimoku Ren, the elegant woman Hone Onna, and the elderly, monk-like Wanyūdō—execute the sentence, dragging the target into a horrific and personalized vision of hell.

Ai Enma herself is a quiet, stoic figure with striking red eyes, always dressed in a traditional black school uniform. She lives in a twilight realm with her three servants and her equally enigmatic grandmother. Her assistants, each bound to her by their own pasts, take the form of the straw dolls and assist in delivering the damned. While the early episodes focus on the revenge-of-the-week format, a notable overarching narrative arc begins around the eighth episode with the introduction of a journalist named Hajime Shibata and his young daughter, Tsugumi. Hajime, a former blackmailer, begins investigating the disappearances linked to the Hell Correspondence website. His daughter, Tsugumi, possesses a strange psychic connection to Ai Enma and can see her when others cannot. As the series progresses, Shibata and his daughter become increasingly entangled in the supernatural system, struggling to understand Ai’s nature and attempting to intervene in the fates of those about to make the irreversible contract. Their investigation provides a critical human perspective and a running moral counterpoint to the show's central, unsettling question: is revenge worth an eternity in hell?.