Description: One summer, fifteen kids innocently wander into a nearby seaside cave. There they meet a strange man who invites them to play an exciting new video game. This game, he explains, pits a lone giant robot against a horde of alien invaders. To play the game all they have to do is sign a simple contract. The game stops being fun when the kids find out the true purpose of their pact.Viz MediaThe extra story Bokurano Mou Hitotsu no Bokurano (Yet Another Bokurano ran after the completion of the main story.