Mario and Luigi are two plumbers from Brooklyn who have just left their jobs to start their plumbing business, however they are not doing very well. They, however, want the recognition of others, which is why in a large water leak in Brooklyn they try to undermine the situation. Such is the surprise of our two characters that this event would make them enter an alternate world in the mushroom world. In this place they will meet Princess Peach and her bitter rival Bowser who wants to conquer all the surrounding kingdoms and thus also win Princess Peachs love. Will our heroes Mario and Luigi be able to stop it?