Four years ago, the "Card Monsters" came to this world, and a terrible disaster erupted.
Their sudden arrival in the human world brought no goodwill, only slaughter and destruction.
To fight them, the special organization "SPOON" was established, and it developed seven sets of warrior Systems: Smog, Chillbreath, Voltstrike, Gustwhirl, Blazeshot, Beamray, and Sonicecho.
With these seven Systems, humanity gained the ability to wield the power of the Card Monsters and a powerful means of fighting back against the creatures.
Yet just as peace seemed within reach, an upheaval known as betrayal took place...
