Summary
Legend says that every 1000 years on October 31, the ghost of the Serpent King Shin Orochi will unleash his evil minions to prey on the living for 5 days nonstop. A high school is invited to go to the very island for a festival. They decide to go, especially because it's October 31 and the 1000th year. What's the worst that could happen? After all, it's just an old legend, right?