Mario & Luigi: Bowser's Inside Story is an RPG for the Nintendo DS. Is is the third and, to date, the final of the Mario & Luigi games. This game features not only Mario and Luigi as protagonists, but Bowser as well.
Many Toads in the Mushroom Kingdom are infected by a mysterious disease that is soon known as the Blorbs, which makes them big and round and unable to move. Princess Peach holds a conference in her castle with the Toads who haven't been blorbed yet. They soon realize that the source of the Blorbs is a weird mushroom that all the victims said they have eaten, and bought from a strange merchant with a cape. Soon, they notice that Mario and Luigi are not there. Eventually they arrive. Peach has enlisted the help of a Star Sprite named Starlow, but even she does not know how to cure the Blorbs. Just then, Bowser attacks and tries to kidnap Peach, but Mario easily defeats him. He is kicked out of the castle and sent flying into Dimble Wood. There, he meets Kamek. He soon finds a strange merchant who sells him a mushroom that he says will help him defeat Mario. Bowser takes it and eats it. However, it is really a Vacuum Shroom, causing Bowser to inhale everything in sight. The merchant turns out to be Fawful, who is a previous and mutual enemy of both Mario and Bowser. Bowser runs over to Peach's castle and inhales Mario, Luigi, Peach, Toadsworth, Toadbert, Starlow, and several Toads. Bowser collapses afterwards.
Inside Bowser, Mario wakes up. He soon finds Luigi and Starlow. Eventually the Mario Bros. find two hammers. They soon reach Bowser's Funny Bone and Mario hits it with a hammer to wake Bowser up. Bowser wakes up in Cavi Cape, with no memory of his time under the influence of the Vacuum Shroom. Starlow talks to Bowser and tells him her name is Chippy. She does not reveal the presence of anyone else inside him. Bowser soon discovers that he can't breathe fire anymore. He soon runs into Fawful and his minion, Midbus. They say they have taken over Bowser's castle. Bowser fights Midbus, but is unable to block his body slam attack and runs off. He sets out toward his castle to take it back from Fawful. At one point he hears a mysterious voice tell him about Chakroads, which are portals that can teleport him to any other Chakroads in the Mushroom Kingdom once he awakens them.
Bowser reaches Plack Beach, where he finds a block collector, Broque Monsieur, on an island trapped in the ocean due to the bridge being destroyed. When a reward is mentioned, Bowser grabs a rope and pulls on it to pull the island to shore. For him to do this, Mario and Luigi power up his arm by playing a minigame. Broque gives Bowser a Vacuum Block, which allows him to inhale the smaller enemies for the Mario Bros. to fight. He soon finds the Sea Pipe Statue, which Starlow says is made to honor a hero. Bowser thinks that he is that hero, but seeing that it is a Blooper he starts to attack it. Fawful brings it to life and it attacks Bowser, but Bowser defeats it, inhaling the Stone Blooper so the Mario Bros. can damage it and make it easier for Bowser to cause more damage. When the statue returns to normal, water pours out of the pipes. Bowser drinks it, which fills the Pump Works area with water and allowing Mario and Luigi to access new areas and get Attack Pieces for an attack.
Eventually the Mario Bros. reach Bowser's Flame Pipe, which is being blocked by a giant bug named Scutlet. The Mario Bros. defeat Scutlet, and when it is destroyed, Bowser can breathe fire again. He soon runs into Broque again, who says that his dog, Broggy, ran off. Broggy returns, but is in a rage. Bowser defeats him by breathing fire at him and punching his back, and he calms down. Bowser then enters the Dimble Wood. There, he finds Broque in his shop, asking him to find 15 Blitties for him (Blocks that resemble cats and who were captured by monsters), and saying he will lend him Broggy if he finds them all. Bowser soon finds three of his minions, Private Goomp, Sergeant Guy, and Corporal Paraplonk, trying to find a Banzai Bill for a giant Bill Blaster so they can fire it at Bowser's castle and take it back from Fawful. Bowser goes to look for one. He rescues some Goombas that Fawful has imprisoned, with help from Mario and Luigi powering up his arm, and uses them as a special attack called Goomba Storm in battle. He finds a giant carrot that he thinks could be a suitable Banzai Bill replacement, and pulls it out (with the Mario Bros. again playing the arm minigame, although this one is different than the last two times). A local Wiggler tells Bowser to take responsibility and eat the Giga Carrot. Mario and Luigi go to his stomach, the Gut Check, and help digest the carrot so Bowser can eat it all. The Wiggler then attacks Bowser in anger for eating the carrot (despite that it was he who told Bowser to eat it), but Bowser defeats him and he hands Bowser a Banzai Bill and tells him not to harm any more crops.
On his way back to the bill blaster, Bowser suddenly gets a horrible stomachache, as something was in the carrot he ate. The Mario Bros. go to the Nerve Cluster and see a wormlike creature named Durmite sucking energy from Bowser to get bigger. The Mario Bros. defeat her, shrinking her down to a small size. They then find Toadbert and hit a switch, which modifies Bowser's arm and he learns the move "Sliding Punch". He soon returns and places the Banzai Bill in the bill blaster and fires the Banzai Bill at his castle. However, it has been modified by Midbus into a machine that can fly, and he moves it out of the way to dodge the attack, and then sets it on top of Bowser, nearly crushing him to death, but Mario and Luigi go to the Rump Command and ford the adrenalne channel to spike his energy and turn him into Giant Bowser. He fights his castle, which Midbus is controlling and sending enemies after him, and defeats them all, and Midbus retreats with the castle to its usual spot, though still in the air. Bowser returns to his original size. He asks Starlow to do this again so he can crush Fawful, but she says it only works when he is in mortal danger. Bowser goes to the path to his castle, and rescues some Shy Guys that Fawful locked in a cage, and they become his next attack, Shy Guy Squad. Midbus fires an iron ball at Bowser, but with Mario and Luigi powering his arm up again, he throws it at the castle, damaging it so it can't fly anymore, and setting it down where it was before.
Bowser enters his castle to find that Fawful has turned it into the Fawful Theater. He goes into the audience, where many of his minions have been brainwashed by Fawful. He finds all the seats to be full, but a Goomba gives him a seat reserved for him. Fawful announces Bowser to be the special guest, and brings him onstage to fight Midbus in a caged battle. As he earlier learned from Broque to duck, this stops Midbus's body slam (and damages him as well due to Bowser's shell being spiked), and Bowser defeats him, knocking him out. Fawful and some Boos take Bowser to a room full of food and snacks as a victory feast. Bowser eats until he is full, but the Boos force him to eat more until he gets fat and falls through the floor, and gets stuck in it. This was Fawful's plan all along. This also creates a new area of Bowser, the Flab Zone.
The Mario Bros. enter the Flab Zone. After getting a new attack, they find Princess Peach being kidnapped by a monster, Alpha Kretin. They use a spin attack that they previously used in their adventures and knock Kretin off of Peach, but he returns. The Mario Bros. defeat him. Now that the Mario Bros. have found Peach, they try to decide how to get out of Bowser. Fawful, in the meantime, tells Bowser that he needs Peach. Bowser realizes for the first time she is inside him. Peach says Fawful must want her because only her power can awaken the Dark Star, an ancient and very evil artifact that was sealed below Toad Town, and if anyone evil gets it, they can become extremely powerful and rule the world. Fawful uses a device to extract Peach from Bowser. Fawful and Midbus take her away, and Fawful sets Bowser (who then falls through the hole in the floor) up on a magic treadmill, literally burning away all the fat and setting him on fire. Bowser walks over to a Bob-omb, but the fire lights its fuse, and it walks over to hundreds of Bob-ombs, causing them all to explode and send Bowser flying into a cave below Cavi Cape.
There, Bowser meets the Monty Bros., some Monty Moles who Bowser previously assigned to dig a tunnel to Toad Town. They are having difficulty doing this, so Bowser takes the digging device himself. With Mario and Luigi powering up his legs, he reaches Toad Town before its battery dies. Bowser enters a building, but is zapped by a trap and knocked out. This makes a new area, the Pipe Yard, accessible for the Mario Bros. It is full of pipes Bowser inhales. They go through a pipe and enter the underground Toad Town. They go in search of the Dark Star, and soon find it just as Fawful breaks its seal on it and steals it. The Dark Star creates a blockade in front of Peach's castle. The Mario Bros. reach Toad Town and talk to Doctor Toadley. Bowser suddenly enters, but the Mario Bros. defeat him. Toadley says that there are three Star Cures that can smash the blockade, and each is held by a Sage. He says the first Sage is in Dimble Wood, and so Bowser heads off to take it himself. Shortly after he leaves Doctor Toadley gets an image of the first Sage: Durmite, who is still inside Bowser.
Mario and Luigi go inside Bowser through a pipe in Toad Town and immediately see Durmite and chase after her, but are unable to follow her when she, much smaller than them, goes under some green blocks that are blocking their path. They decide to leave the work to Bowser for now, as he can't get the Star Cure if it is inside him. Bowser goes to Blubble Lake and rescues some Koopas, with the Mario Bros. playing a minigame inside his nose to make him sneeze and move a giant object across the lake to form a bridge that he can use to get to the Koopas, who become Bowser's next attack. Bowser finds a tower, the Tower of Yikk, and activates it. The tower stomps on Bowser, but the Mario Bros. ford the adrenaline channel again and he becomes Giant Bowser and defeats the tower. After returning to his size, he enters the now lifeless tower and meets the ghost of its owner, Yikk, who is studying Boo Rays. Bowser stands in the Boo Ray and this makes the green blocks inside him disappear, allowing Mario and Luigi to continue their pursuit of Durmite in the Energy Hold. Eventually she talks, for the first time, and tells them to stop chasing her. She refuses to acknowledge them as heroes or give them the Star Cure, and fights them, turning into another form called Wisdurm for most of the battle, but they defeat her. She turns into a butterfly and gives them the Star Cure, and leaves through a doorway. The Mario Bros. enter another area where they activate his Body Slam ability.
Starlow tells Bowser they got the first Star Cure. Bowser soon meets up with Private Goomp, who has been separated from the others. He reminds Bowser that he stole something that might be a Star Cure from a Koopa in Plack Beach, and it is now inside a safe in Bowser's secret vault. Bowser goes to his castle to find it. He explores new areas of his castle, also rescuing some Bob-ombs Fawful imprisoned. He finally reaches his vault, only to find that the Monty Bros. have built a railroad into it for a train, the Fawful Express. The Monty Bros. have betrayed Bowser for Fawful, and hit Bowser with the Fawful Express, but Mario and Luigi turn him into Giant Bowser again and he fights the Fawful Express. He eventually destroys it, presumably killing the Monty Bros., and goes to open his safe. However, due to being hit by the train he forgets the combination. The Mario Bros. go to his memory banks to find the memory, and are attacked by an anti virus program, in the form of Bowser Memory ML, digital versions of Mario and Luigi. The Mario Bros. defeat them, and another program takes the form of Peach and gives the Mario Bros. the broken memory, which they put together like a puzzle. Bowser remembers the combination and opens the safe and takes the second Star Cure. However, Private Goomp, Sergeant Guy, and Corporal Paraplonk lock him in the safe, as they have also betrayed him for Fawful. They throw him in the trash somewhere. Bowser eats the Star Cure as it caused him so much trouble, and Mario and Luigi go to his stomach and take it.
The Mario Bros. leave Bowser through a pipe and ask Doctor Toadley about the third Star Cure. He says that the third Sage lives on a cliff in Plack Beach. The Mario Bros. go to the top of the cliff, with Mario inhaling air from a pipe to blow up like a balloon, until they reach the third sage, Chakron, who is meditating and who is the master of Chakroads. Since he was snapped out of his meditative state, he asks the Mario Bros. to knock him over. They do not know any attacks that can, so he tells them to find such an attack in Dimble Wood. They go and find some attack pieces, and when they find six, the Wiggler lets them go through to get the other four. Mario is captured by a Sockop, and Luigi goes after him and follows them as they all jump into the mouth of the giant boss Sockop. Luigi attacks him from the inside and he spits out Mario and shrinks down to regular Sockop size, with Luigi still inside him. He is unconscious now, so Luigi is able to move, with the other Sockops thinking he is one. After getting three of the four remaining attack pieces, he eventually finds the Sockop that captured Mario arguing with two more Sockops over who should eat him. The boss sockop recovers after Luigi gets out of it. Mario and Luigi defeat the four Sockops, and once they are destroyed the Mario Bros. get the last attack piece for the Snack Basket attack, which shakes the ground.
Mario and Luigi use this attack to knock Chakron over. He jumps off the cliff, but assumes a new position, upside-down, comes back up, and gives the Mario Bros. the third Star Cure. They take the three Star Cures to Doctor Toadley, who combines them into the Miracle Cure, which cures the Blorbs. The Mario Bros. use it to smash the blockade and enter Peach's castle. They eventually reach the garbage area and encounter Midbus, who creates a monster named Junker out of the garbage. The Mario Bros. defeat Junker, who throws a safe, smashing it and releasing Bowser, and then smashes through a door and is destroyed. The Mario Bros. decide to leave the rest to Bowser, and enter him through a pipe. His back is injured from when the safe was smashed, so the Mario Bros. heal it (which takes so long, that Toadsworth and Toadbert drink some tea), and in the process make him more flexible so he can curl up in a ball and cross spikes and climb some walls.
Bowser goes through the castle and soon finds Fawful, who has nearly finished using Peach to awaken the Dark Star. Fawful transforms Midbus into Blizzard Midbus to fight Bowser. Bowser defeats him. Blizzard Midbus falls, and is frozen, except for his head, with icy mist coming out from his nose. Fawful awakens the Dark Star and absorbs energy from it, but Bowser punches him away before he can finish. The Dark Star enters Bowser, who inhales the mist from Midbus's nose to ease the pain from the Dark Star. This freezes his airway, and the Mario Bros. chase after the Dark Star, having Bowser freeze and unfreeze when necessary. The Dark Star absorbs Bowser's DNA and gains his abilities. Eventually they catch the Dark Star and defeat it. It is seemingly destroyed, but leaves Bowser through his mouth and takes the form of an incomplete Dark Bowser. He is incomplete because Fawful took some of his energy, and needs him to become complete. He inhales Peach and realizes she isn't the one. When he hears Fawful searching for the Dark Star, he goes after him.
Fawful is now Dark Fawful due to absorbing the dark power, and transforms Peach's castle into a robot that fights Bowser, but Bowser defeats it and it turns back to normal. Bowser fights Dark Fawful and defeats him, destroying his body but reducing him to a bug form, as he cannot die while the Dark Star, whose power he absorbed, exists. Dark Bowser inhales Dark Fawful and becomes complete. Bowser chases after him, at one point getting into a spike ball fight with him. Eventually they reach the top of Peach's Castle, where Dark Bowser has spit out Peach and is now shrouding the world in darkness to destroy it. Bowser is not about to let the world be destroyed, as he wants to rule it someday. He fights Dark Bowser, but right when he has him down, Dark Fawful, who is now combined with the Dark Star Core, heals him. Bowser attacks him to make him cough up Dark Fawful, and then inhales him for the Mario Bros. to fight. This repeats until Mario and Luigi destroy the Dark Star Core, immobilizing Dark Bowser and allowing Bowser to finish him off.
Light and peace return to the Mushroom Kingdom. With Dark Bowser gone, Bowser can now kidnap Peach. Fawful is still alive, but just a head, and near death. He appears before the Mario Bros. and says he has remorse, but is really trying to trick them, and selfdestructs in a final attempt to destroy them. Instead, the explosion forces them and everyone else out of Bowser. Bowser is furious to discover that Mario and Luigi were inside him, and they fight as the credits roll. Mario and Luigi easily defeat him and he ends up in the hospital. Private Goomp, Sergeant Guy, and Corporal Paraplonk ask Bowser to forgive them and let them rejoin his minions. Bowser receives a present from Princess Peach, with Starlow inside it saying Peach suspected he would attack her castle again soon. Bowser accepts Private Goomp, Sergeant Guy, and Corporal Paraplonk back as his minions and tells them to help rebuild his castle and to do better fighting Mario next time. Bowser then opens the present, which is a cake that has Bowser drawn on it and figures of Mario, Luigi, and Peach.
- Fawful / Dark Fawful
- Princess Peach
- Midbus / Blizzard Midbus
- Kamek (possibly)
- Private Goomp
- Sergeant Guy
- Corporal Paraplonk
- Monty Bros.
- Durmite / Wisdurm
- Alpha Kretin
- Doctor Toadley
- Peach's Castle
- Dark Star / Dark Bowser
- Bowser (Mario)
- Midbus (Bowser) (unwinnable)
- Sea Pipe Statue (Bowser, Mario Bros.)
- Scutlet (Mario Bros.)
- Broggy (Bowser)
- Wiggler (Bowser)
- Durmite (Mario Bros.)
- Bowser's Castle (Giant Bowser)
- Midbus (Bowser)
- Alpha Kretin / Beta Kretin (Mario Bros.)
- Bowser (Mario Bros.)
- Tower of Yikk (Giant Bowser)
- Wisdurm (Mario Bros.)
- Fawful Express (Giant Bowser)
- Bowser Memory ML (Mario Bros.)
- 3 Shroobs (Mario Bros.) (super boss)
- Junker (Mario Bros.)
- Blizzard Midbus (Bowser)
- Dark Star (Mario Bros.)
- Peach's Castle (Giant Bowser)
- Dark Fawful (Bowser)
- Dark Bowser (Bowser), Dark Fawful & the Dark Star Core (Mario Bros.) (final boss)
- Dimble Wood
- Cavi Cape
- Plack Beach
- Bumpsy Plains
- Bowser's Castle Path
- Bowser's Castle
- Cavi Cape Cave
- Toad Town
- Blubble Lake
- Tower of Yikk
- Peach's Castle