Z/X: Ignition
The story is put from the not-so-distant future. Five"Black Points" unexpectedly appeared round the world as portals to parallel worlds. Just strange creatures began their intrusion. These creatures are five worlds' inhabitants --exactly the worlds in different time frames. As a way to make sure their own future interval succeeds, the five invasion forces each battle to wipe out one future timeframes that are other. The key would be one product.