High above Farmless City, citizens are stunned by the sudden appearance of two floating figures. Are they human boys, monolithic robots, or something much more strange? As the battle ensues between them, destruction and devastation falls on the hapless city. One figure is Vice, and seems to be as evil as his name implies. The other is Ultimo, intent on trying to stop Vice from wreaking more havoc.

Their battle ends in a draw and the two vanish. Now we go to Yamato; a normal high school student that forgot to get his crush a birthday gift! Willing to trade his scxhool bag for what he needs, he runs into an antique shop and sees a tattered, yet amazing doll. For an unknown reason, he simply says "Ultimo..." and Ultimo awakes.

But who are Vice and Ultimo really? Where did they come from? A new mystery begins with the fate of the world possibly hanging in the balance!