Seeking well-deserved rest and relaxation, Mario and Princess Peach travel to a beautiful remote island. However, when they get to the island, they quickly find out a mustachioed maniac has mucked up the entire island, and Mario is acc of committing the crime. Armed with a hi-tech water cannon called FLUDD (Flash Liquidizer Ultra Dousing Device), Mario sets out to clean the island, clear his name, and solve the mystery of the villainous vandal.