The curse involves a vagrant's ghost who, after dying from a fall caused by a man, vows that the man will experience a despair greater than his own at the peak of his happiness. This curse leads to a surreal trial where the man's happiness is threatened by the spirit's demand, involving throwing popcorn in the air and catching it, with failure resulting in death.

Rohan Kishibe visits a church in Venice and accidentally enters the priest's side of a confessional booth. There, a man begins to confess a terrifying story about a curse from 25 years ago. Rohan, posing as the priest, listens to the confession, which draws him into the unfolding supernatural events.

Venice is the primary setting where the story unfolds, including iconic locations such as St. Mark's Square and the Church of Saint Roch. The city provides the backdrop for the man's confession, the curse's origin, and the surreal events that follow, emphasizing the atmosphere of mystery and history.

The popcorn trial is a supernatural challenge set by the vagrant's spirit to the cursed man. He must throw a piece of popcorn higher than a lamppost and catch it in his mouth three times in a row to have the spirit leave him forever. Failure results in the spirit cutting off his head, symbolizing the high stakes of the curse and the man's desperate attempt to escape it.

The story contrasts the man's long avoidance of joy due to the curse with his eventual experience of true happiness upon seeing his daughter play. This peak happiness triggers the curse's trial, highlighting the tension between joy and impending despair. The narrative uses this to delve into destiny, suffering, and the supernatural consequences of past actions.