The Future Diary

Sakaido is a genius detective who can track down any criminal. But when his daughter is murdered, revenge lands him on the other side of the law. Now in prison, he helps the police solve mysteries using a system that invades a person’s identity. Little by little, a trail of blood forms, and it all leads back to his daughter’s murderer.

During a summer camp, 15 children, 8 males and 7 females, find a grotto by the sea. Deep within they discover working computers and some electronic equipment, and later the owner, a man called Kokopelli. Kokopelli claimed to be a programmer working on a brand new game, in which a large robot has to defend the Earth against fifteen alien invasions. He persuades the children to test the game and sign a contract. All but one of them signs; barely a moment later they mysteriously awaken on the shore believing what happened was just a dream.

A supernatural system allows people to take revenge by having other people sent to Hell via the services of a mysterious entity and her assistants who implement this system. Revenge, injustice, hatred, and the nature of human emotions are common themes throughout the series.

With his two friends, a video-game-obsessed young man finds himself in a strange version of Tokyo where they must compete in dangerous games to win.