The spectral entity "Portergeist" manifests as an elongated face, embodying a violent poltergeist force tied to a cursed publication. It arrives alongside the Kyoufu Shinbun (Horror Newspaper), a daily paper predicting future deaths and calamities that materializes unnaturally – hurled through windows, for instance.

Reading this newspaper forges a bond with the poltergeist and seals the reader's fate, reducing their lifespan to precisely 100 days. Portergeist actively torments subscribers throughout this countdown, subjecting them to escalating supernatural dangers. Its presence directly correlates with the newspaper's grim forecasts, actively influencing or causing the reported tragedies and disasters, forcing readers to witness or endure them.

The poltergeist acts as both instigator and manifestation of the horrors encountered during the 100-day ordeal. Ignoring or avoiding the newspaper offers no protection; the entity persists relentlessly until the subscriber's death at the countdown's end or through successful spiritual countermeasures. Some desperate individuals investigate the poltergeist's origins or seek to break its curse by confronting haunted locations detailed in the paper.

Portergeist's exact nature remains shrouded in mystery, though it displays intelligence in actively orchestrating events. Its link to the newspaper suggests it could be a collective manifestation of malice or a spiritual punishment for engaging with the cursed publication. Throughout the haunting, the entity adapts its manifestations based on the reader's actions and the newspaper's evolving predictions.