The story features a group of university students (Including you) from Tokyo, who are part of an archeology club. One day, the six boys decide to leave for Kikuchi island via yacht and almost having reached their destination they see a column of smoke rising from an area of ​​the island. Higashiyama, the largest of the group, decides to immediately dive into the water to find out what is happening but as soon as he arrives on land he is attacked by a mysterious man wearing a pig's mask who brutally hits him with a hammer.

The companions see the scene in the distance and are stunned; one of the girls, Uehara, in love with Higashiyama, asks the group to help her companion and after much insistence, you decides to dive in to reach the place where the massacre took place. While you’re swimming, you notices that the seabed is full of bins of radioactive waste and that the yacht has sunk, but luckily all the members of the group arrive safely on the island. Shortly afterwards they see a fire in which the remains of a body are burning, but there is no trace of their friend Higashiyama. After some discussions on what to do, where nervousness is increasingly greater, you and your companions opt to try everything and everything to reach the village they had previously glimpsed, but this will only be the beginning of a game of survival where blood and desperation will be dominant.