Saving the world is no child’s play in this dark and chilling mecha manga series. 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 one 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. 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.