
After being sucked into a drain pipe, Mario and Luigi defend the Mushroom Kingdom from King Koopa.

Mario and Co head to the Linguini Empire to attend a benefit spaghetti dinner; when they arrive, Princess and Toad are separated from the Marios and meet Koopa, who's taken over.

Desperate for cash, the Mario brothers trade the royal cow for bean seeds; Princess scolds them, and accidentally sneezes, blowing the beans into the yard. Overnight, they grow into a beanstalk.

Mario and Co arrive in Rotunda Land, which is ruled by the uptight Queen Rotunda; after being caught, Mario unintentionally gets Rotunda to drink a love potion, causing her to fall in love with him, much to his dismay.

To help Toad pay off his debt to Fry Guy, Mario and Luigi enter a bike race in hopes to collect the prize money; what they don't know is that it's all a trap planned by Koopa.