Do You Princess Toadstool Take This Koopa...?
At Koopa's castle, Mario and Luigi are locked in a cell in King Koopa's dungeon, where King Koopa himself is taunting them as Princess Toadstool and Toad stand nearby, guarded by two Koopa Troopas. As King Koopa jeers Mario and Luigi, Toad boldly runs forward and begins to taunt King Koopa himself, running around him claiming he's unafraid of him; ignoring Princess Toadstool's warnings, Toad continues to run around King Koopa, who, annoyed with Toad's antics, decides to use his magic wand to turn him into a large, green rock, a fate which has befallen several other Mushroom People as well.
As Princess Toadstool hugs the stone that was once Toad and bemoans his fate, a mocking King Koopa exclaims that Toad isn't the only one he isn't getting rid of, and proceeds to pull a nearby lever, which causes the walls of Mario and Luigi's cell to begin to close. Seeing Mario and Luigi in peril, Princess Toadstool begins to beg King Koopa to let them live, saying that she will do anything for him, which interests King Koopa. Deciding to agree to Princess Toadstool's bargain, King Koopa tells her that she must marry him and make him the legal ruler of the Mushroom Kingdom. Seeing her hesitance, Mario and Luigi, who are trying in vain to push back the walls of their cell, tell her just to go through with it, promising her that they will break free and help her get out of this mess (though Luigi is somewhat reluctant, of course). With this, Princess Toadstool agrees to marry King Koopa, on the condition that he frees Mario and Luigi and changes Toad and the captured Mushroom People back to normal; hearing this, King Koopa makes the promise that he will change Toad and the Mushroom People back to normal before he is married to Princess Toadstool and will free Mario and Luigi after he is, which Princess Toadstool hesitantly agrees to.
With his deal with Princess Toadstool done, King Koopa pulls the lever on the wall again, which instantly causes the moving walls of Mario and Luigi's cell to stop moving inward and to pull back. After sparing Mario and Luigi, King Koopa tells his two Koopa Troopa cohorts to take Princess Toadstool to the great hall of the castle and to spread the news that he and Princess Toadstool are going to married in the morning the next day. After announcing this, King Koopa leaves the area, descending a ladder that Princess Toadstool, escorted by the two Koopa Troopas, follows him down. As King Koopa, Princess Toadstool and the Koopa Troopas leave, Luigi exclaims how everything that has happened so far is terrible and that he and Mario need to stop Princess Toadstool and King Koopa from getting married. Agreeing with Luigi, Mario, and his brother, each take out a spoon and begin to quickly dig out of the cell they are in.
Elsewhere in the castle, King Koopa is climbing a ladder while throwing flowers downward; as soon as he reaches the top of the ladder and gets on to a platform, where three Koopa Troopas are, King Koopa trips and is sent sprawling forward. Lying on the ground, dizzy and stunned, King Koopa tells the surrounding three Koopa Troopas that he is going to be marrying Princess Toadstool. Mario and Luigi, having rapidly dug a long tunnel with only their spoons, soon break through a wall and into a room that has two Hammer Brothers in it. As the Hammer Brothers prepare to attack them, Mario and Luigi quickly go back into the tunnel they've dug, causing the Hammer Brothers to accidentally hit each other on the head with their hammers when they do attack.
In the great hall of his castle, King Koopa is in the midst of being helped into his wedding jacket by Mouser, as a large amount of Koopa Troopas begin to decorate and clean the great hall; as Mouser struggles to button King Koopa's jacket, King Koopa grabs a passing Koopa Troopa and tells him to prepare a band for his wedding, a loud one. Kicking the Koopa Troopa away, King Koopa turns to Mouser and tells him to make a guest list for the wedding and to invite all his friends, and proceeds to kick Mouser away. Getting off the ground and taking out a notepad, Mouser asks King Koopa to tell him what friends to invite, a question which causes King Koopa to walk around and think for a few seconds. Eventually, King Koopa, frustrated, simply tells Mouser to invite his mother to the wedding, saying she'll come for the wedding cake. After saying this, the button on King Koopa's jacket pops off and flies forward, hitting Mouser in the eye and causing him to drop his notepad and pencil. After this occurs, King Koopa, after picking Mouser up by the neck, yells that he can't get married in this jacket, to which the nearby Princess Toadstool responds to by saying he won't be getting married at all. Dropping Mouser, King Koopa asks Princess Toadstool why that is, to which she responds to by saying that King Koopa hasn't turned Toad and the Mushroom People back to normal like he promised; flustered, King Koopa relents to Princess Toadstool's demands and brings her to a nearby room.
Upon entering this room, King Koopa, after being reminded to transform Toad and the Mushroom People back to normal by Princess Toadstool once more, waves his magic wand through the air, which causes several nearby, green rocks to change back to normal Mushroom People, Toad among them. As a bewildered Toad wonders what has happened, a happy Princess Toadstool hugs him and tells him he doesn't want to know.
Underground, beneath King Koopa's Castle, Mario and Luigi are still digging tunnels; as Luigi continues to dig, he states to Mario that they've begin digging a long time; then, Mario proceeds to tell Luigi to trust him, saying he has an instinct about these things. Above ground, two Koopa Troopas open a door, allowing a large amount of joyous Mushroom People to run out of the castle. As the Mushroom People flee, Toad solemnly walks out of the castle and, while crying, tells Princess Toadstool to not marry King Koopa, saying he'd rather be a rock then allow Princess Toadstool and King Koopa to marry. Sadly, Princess Toadstool, while hugging Toad again, tells him that she has to marry King Koopa. Angrily shaking his fist at King Koopa, Toad says he can't allow this wedding to occur; seeing Toad doing this, King Koopa orders two Koopa Troopas to throw Toad away, which they do, into a nearby group of Mushroom People.
As Princess Toadstool says goodbye to Toad and the Mushroom People and goes back into the castle with King Koopa and the two Koopa Troopas, Mario and Luigi emerge from the ground nearby and, after realizing that they're not in the castle anymore, notice Toad and the Mushroom People standing nearby. Luigi is surprised that King Koopa kept his promise, but Mario is highly skeptical. As Mario and Luigi watch from their hole, King Koopa suddenly bursts through the doors of his castle and reveals to Toad that he has no intention of keeping his promise to Princess Toadstool and prepares to change Toad and the nearby Mushroom People back into rocks. As they try to run from King Koopa, Toad and the Mushroom People are changed to stone once more by him; Mario silently badmouths Koopa (calling him a "fang-faced, two-timin', double-crosser"), and Toad shouts that Koopa won't get away with it. After taunting Toad as he changes into a rock, King Koopa orders a nearby trio of Koopa Troopas to move the green rocks that were once Mushroom People back into his castle, stating he doesn't want Princess Toadstool to notice something is amiss until after he marries her.
As the three Koopa Troopas move the rocks back into the castle, Mario gets an idea on how to get into the castle unnoticed; later, Mario and Luigi, both of whom are dressed as caterers and carrying trays, approach the door of King Koopa's Castle and knock, alerting a Koopa Troopa to their presence. Introducing themselves as caterers, Mario and Luigi are subsequently denied access into by the Koopa Troopa doorman, who says the castle has no need for caterers. Not giving up, Mario knocks on the castle door again, and when the Koopa Troopa answers once more, Mario states that he and Luigi are delivering bug soup for King Koopa's wedding; at the mention of bug soup, the Koopa Troopa begins to lick his lips and happily lets Mario and Luigi into King Koopa's Castle, much to Luigi's astonishment and surprise. As Luigi stands dumbstruck, Mario reminds him that they need to save Princess Toadstool and quickly rushes into King Koopa's Castle.
In the castle, Princess Toadstool is covering her ears as three nearby Koopa Troopas play a trumpet, a violin and a drum terribly; eventually stopping the three Koopa Troopas from playing their instruments, King Koopa begins to tell them that they have to play better and put more feeling and romance into their music. Before he can continue to talk, King Koopa is interupted by his mother, who appears descending some stairs and quickly rushes over and hugs her stunned son, claiming she's so happy that he is finally getting married and settling down. Finishing hugging King Koopa, as well as pinching him, King Koopa's mother looks over and sees the nearby Princess Toadstool and announces that, after Princess Toadstool and King Koopa are married, she wants the two to spend their honeymoon with her, in the foulest, smelliest swamp in seven worlds. Hearing this, Princess Toadstool lets out a sob, as King Koopa's mother goes over to her son and surmizes that Princess Toadstool must be overcome with joy to be getting married, explaining her crying.
Nearby, Mario and Luigi are walking down a hallway, where Mouser notices them; telling them to stop, Mouser, along with two Koopa Troopas, approach Mario and Luigi and proceeds to ask if he knows them from somewhere. Winking to each other, Mario and Luigi throw their trays up into the air and begin to play Patty Cake with each other, distracting Mouser and the two Koopa Troopas; finishing their game, Mario and Luigi grab their trays when they fall back down and proceed to throw them at Mouser, who dodges the first tray, only to be knocked backwards by the second one. Fleeing the scene, Mario and Luigi take off their caterer outfits and leave them behind.
Having traveled through King Koopa's Castle, Mario and Luigi, after going down a spiral stairway, find themselves in a room filled with large green rocks. As Luigi sits on a rock, saying that he and Mario will never find Princess Toadstool, Mario tells him that he's sitting on the rock that was once Toad. Leaping off Toad, Luigi apologizes to him and hears an idea Mario has, as Toad presumably knows his way through King Koopa Castle, all that they need to do is find King Koopa's magic wand and use it to change Toad back to normal and he can lead them to Princess Toadstool. After voicing his idea, Mario leaves the room and has a complaining Luigi, who is forced to carry the rock that was once Toad, following him. As he climbs a ladder, Mario notices a Koopa Troopa pushing a wedding cake along a bridge and tells Luigi, who is struggling to climb the ladder and carry Toad at the same time, that they must be getting close to Princess Toadstool.
In the great hall of King Koopa's Castle, the Koopa Troopa with the wedding cake wheels it nearby, as King Koopa's mother says that the wedding should start; after saying this, King Koopa's mother notices that King Koopa isn't dressed for his wedding, and immediately has her panicking son leave and get dressed. Leaving the great hall, King Koopa approaches Mouser, who is busy sewing King Koopa's jacket, and tells him to to hurry, or else he'll turn him over to his mother. Peaking out from behind a curtain, Mario sees King Koopa and tells the nearby Luigi that he's going to take his magic wand and use it to change Toad back to normal. Setting down his magic wand on a table, King Koopa puts his jacket and pants on and admires himself in a nearby mirror, before leaving with Mouser upon hearing his mother shrieking, accidentally leaving his magic wand behind. With King Koopa and Mouser gone, Mario rushes out from behind the curtain and grabs King Koopa's magic wand, which transforms him into Super Mario; with King Koopa's magic wand in his grasp, Mario transforms Luigi into Super Luigi and also changes Toad back to normal, which causes the magic wand to overload and disintegrate. With Toad back to normal, Mario asks him to quickly lead him and Luigi to King Koopa and Princess Toadstool wedding, which Toad surmises is in the castle's great hall.
Toad's assumption proves correct, as the wedding, with Tryclyde as it's minister and several Koopa Troopas, Goombas, Mouser and King Koopa's mother as its attendees, is occurring. As Tryclyde begins the wedding by reading from the Bible, King Koopa reminds Princess Toadstool about their deal, which prompts Princess Toadstool to hesitantly begin to say "I do"; before Princess Toadstool can say this, Toad, Mario and Luigi interrupt the wedding with fireballs, causing everyone present to begin to panic. As fireballs fly everywhere, Goombas and Koopa Troopas begin to run in a frenzy, with one Koopa Troopa tripping and falling headfirst into the wedding cake, causing it to collapse, crushing several Koopa Troopas, Goombas, Mouser and Tryclyde, as well as flinging icing into King Koopa's face.
When all the pandemonium dies down, Toad rushes over to Princess Toadstool and informs her that King Koopa had gone back on his word and changed all the Mushroom People back into rocks. Hearing this, Princess Toadstool, furious, scolds the king and tells King Koopa that she will never marry him and, grabbing a piece of the wedding cake, throws it at King Koopa's face, claiming one day he'll get what he deserves before walking away. As Princess Toadstool leaves, King Koopa's mother, enraged, hits her son on the head with a drum and says that she'll have to tell all the relatives that he is still a bachelor. While leaving, King Koopa's mother also tells King Koopa to go sit in the corner for six days, which King Koopa reluctantly agrees to before falling flat on to the ground.
Animation and continuity errors