Every Spriggan is a one-man army-an S-class special operative with unrivaled combat abilities. Tasked with sealing away the dangerous relics of hyper-advanced ancient civilizations, they're the last line of defence against global catastrophe.

Ominae Yu, the Spriggans' ace operator, is caught up in a deadly game of cat-and-mouse with Yama, a sentient computer program from the distant past. Yama has seized control of every last nuke in the world, and if Yu doesn't survive its gauntlet of twisted challenges, it's the end of the line for all humanity!