The action takes place in the not-too-distant future. Five "Black Points" appeared all over the world as portals to alternate realities. Strange monsters began to invade these gateways almost immediately. These beings live in five planets, all of which are the same worlds in various periods. Each of the five invading groups fights to wipe out the other future times in order to ensure their own future timeframe survives. One card-shaped gadget serves as the key.