After a nuclear testing in the pacific a Japanese man named Koichi Shikishima and his son see a strange reptilian creature after making an emergency landing on an island. After returning home Koichi is asked to identify the monster by the government where it's identified as a member of the Titanoceratus family. The creature finally makes landfall on Tokyo where it trashes the city. The military forces Koichi to join them in fighting the monster. Can this terrifying monster be stopped by plan z? Or will humanity fail?