Highschool of the Dead: Drifters of the Dead

After escaping the zombie-infested mainland, Takashi and his companions reach a remote island where they finally seem to have found a place to rest. A deserted seaside shack provides food, clothing, and enough safety for the exhausted group to relax after days of relentless survival.

Their rare moment of peace collapses when smoke from poisonous hydrangeas begins causing powerful hallucinations. With their senses distorted and everyone seeing increasingly absurd versions of reality, the survivors have to escape the island's intoxicating haze before their own minds become the danger.