Mario & Luigi: Superstar Saga is largely set in the Beanbean Kingdom, a country neighboring the
Mario series' usual setting of the
Mushroom Kingdom, mainly populated by Beanish people and Hoohooligans, with many locations named after onamotapoeia representing laughter. The player characters are brothers
Mario and
Luigi, who travel to the Beanbean Kingdom to return the voice of
Peach, the princess of the Mushroom Kingdom, after it is stolen by the Beanish witch Cackletta and her henchman Fawful. Among other characters are Queen Bean and Prince Peasley of the Beanbean Kingdom, who assist Mario and Luigi; and the thief Popple, who crosses paths with them throughout the game. Cackletta and Fawful, disguised as ambassadors of the Beanbean Kingdom, visit Princess Peach's castle in the Mushroom Kingdom and steal her voice, replacing it with explosives that drop from her
speech balloon when she talks. Mario and Luigi are summoned to the castle, and briefly confront
Bowser, who had intended to kidnap Peach, but decides against it due to her explosive speech. The three team up to retrieve Peach's voice, and fly to the Beanbean Kingdom on Bowser's new airship, the Koopa Cruiser. Mid-flight, Fawful attacks them, and Bowser becomes separated from Mario and Luigi after a crash landing on the Mushroom Kingdom side of the Beanbean Kingdom border and being launched from a cannon. After crossing the border and traveling to the peak of Hoohoo mountain, Mario and Luigi defeat a cursed dragon, Dragohoho; freeing Prince Peasley. The brothers then travel to the Beanbean Kingdom, and are invited to the Beanbean castle, where Cackletta – disguised as the royal advisor Lady Lima – tricks them into helping her steal the Beanstar, a mystical item that when awoken by a noble and beautiful voice will grant any wish. Upon freeing Queen Bean from being transformed into a savage beast by Cackletta, the brothers track Cackletta to Woohoo Hooniversity and find her exposing the Beanstar to the stolen voice, causing it to go berserk. Mario and Luigi battle Cackletta, fatally injuring her; Fawful uses his vacuum-equipped helmet to save her soul. Mario and Luigi locate the Beanstar again, which Popple is trying to steal together with an amnesiac Bowser as his sidekick; when it again is exposed to Peach's voice, it shoots into the sky and explodes, scattering across the kingdom. Peach arrives by airport in the Beanbean Kingdom, and Mario and Luigi learn that
Birdo had been used as a
political decoy during Cackletta's visit; the Beanstar became enraged after hearing Birdo's voice. Fawful finds Bowser after he regains his memory, albeit weakened from the Beanstar's explosion, and places Cackletta's soul inside him; she takes control of the body, and takes the name Bowletta. She kidnaps Peach, and demands the Beanstar as ransom; Mario and Luigi collect the pieces, and meet with her in the frozen palace Joke's End to make the exchange. Bowletta refuses to return Peach, so Luigi disguises himself as Peach to be taken in her stead, and reclaims the Beanstar, returning it with Mario to Queen Bean after a final confrontation with Popple, who is later arrested and forced to do community service in Little Fungitown, a community of Mushroom Kingdom immigrants. Bowletta uses Bowser's flying castle to attack the Beanbean Kingdom. Mario and Luigi navigate their way through the castle, expel Fawful, and battle Bowletta. After she vacuums them inside her stomach, they battle Cackletta's soul and exorcise her from Bowser's body, reducing her to nothing and returning Bowser to normal. Peasley blows up the flying castle while the brothers escape. Mario, Luigi, and Peach receive Bowser as a parting gift before taking an airplane home to the Mushroom Kingdom, dropping Bowser off at his new castle mid-flight. == Development and marketing ==