If Mario was real, then the Mushroom Kingdom would be real too, and Bowser's Castle...
Bowser would then try to invade the real world (Earth) and might succeed... unless Mario and Luigi stop him of course. But they live in the Mushroom Kingdom, and might not think about traveling back to the real world...
Hey, what if there was a way to travel to the Mushroom Kingdom or Bowser's Castle?
Mario Maniac!!