Hinamizawa Syndrome is a fictional disease featured in the visual novel series Higurashi: When They Cry. It is characterized by symptoms such as paranoia, hallucinations, and violent behavior, often triggered by stress or trauma. The syndrome is linked to the rural village of Hinamizawa, where it is believed to be connected to the village's dark history and rituals. The disease plays a crucial role in the plot, affecting various characters and their relationships. As the story unfolds, the impact of Hinamizawa Syndrome reveals deeper themes of fear, trust, and the consequences of isolation within the community.