Typically for the series, this turn of events comes about in wacky fashion, with Mario and Luigi finding themselves trapped inside Bowser (after he inhales them, à la Lord Jabu-Jabu), and able to affect the Koopa King's actions directly by the work they carry out within him. Excellently, Bowser (who is controlled with X and Y, as opposed to A and B) has a special attack that sees a small army of Goombas charge enemies.
These delightful details featured in the latest Nintendo Power, along with a basic synopsis of the story. Apparently, Mario and Luigi are searching for a cure to a disease that has swept through the Mushroom Kingdom, causing its denizens to balloon in size -- which explains those obese Toads.
Don't forget to check out the ten new screens we've added to our gallery, and make some time to coo at the stylish Japanese boxart!
Source: Nintendo Power details