Davide and his fiancée Alice aren’t two simple serial killers. They are looking for something inside the bodies of their victims, which forms the mystery of the story. And they will continue to kill people until they find what they are looking for.
In the future, the Japanese government captures a class of ninth-grade students and forces them to kill each other under the revolutionary "Battle Royale" act.
Saya, a half-human, half-vampire, works for a secret government agency. She is sent to a military base for a mission where she tries to find ways to destroy Onigen, the vampire who killed her father.