SMG4 runs out of the Princess Peach's Castle complaining about Mario and his Spaghetti. He complains as to why he buys strange things on eBay, as the video proceeds to show Mario inside the castle, naked, dancing with a plate of spaghetti put on what looks like a model. He screams to the heavens to give him the strength to fight Mario's stupidity, when a rock falls from the sky and hits him.
SMG4 complains that it's just a rock and that he would've been fine if it was a wizard or something similar. The rock reveals a wizard hat and begins talking, which shocks SMG4. It begins floating and wonders if SMG4 has seen him before. SMG4 is still awestruck, as the rock begins asking what SMG4 wants, and suggests if he wants to be a princess. SMG4 tells him that's wrong, he only wants Mario to stop being an idiot. The rock takes it as if he wants to be an idiot too, which SMG4 refuses before being changed to have a moment, before being changed back to realize what he did, and tells the rock off for it. It asks if he wants to become a wizard. SMG4 tries to repeat what he said, when the rock pulls out a wand, flips for a second and launches SMG4 to the other side of the castle. Mario's model also falls out and Mario screams to SMG4, whom it landed on, to get it for him.
A while later, SMG4 wakes up to find a figure approaching him, which turns out to be Hagrid, and SMG4 screams and runs out of his room. He tells Toad someone's trying to kill him but Toad doesn't care. Despite this, he follows SMG4 to the door to peek in on the man. Toad pulls out a gun just as he turns around. Toad mistakes him for Santa and runs towards him, and asks where his 2013 Christmas present was. Hagrid doesn't know how to answer, as Toad begins angrily fighting him, which SMG4 remarks as easy.
Several times, Hagrid follows SMG4 telling him he's a wizard. SMG4 tries telling him this after a while, but Mario thinks he's right, which disappoints SMG4.
SMG4 follows Hagrid, who shows him a portal of a castle and explains he's going to go there to do spells. SMG4 backs away, noting that's fine, backs away slowly and explains he's got to go, but Hagrid knocks him into the portal, sending him to the school. Mario follows him, which he confirms to SMG4.
They're welcomed and are put into the team Mushroomdors (a mock of "Gryffindor"). Bowser and SMG3, other students, are put into Slytherbastards (a parody of "Slytherin") and there're also Team Huffleretards (a mock of "Hufflepuff"), comprised of Steve and a Teletubby. He then tells them to have fun with the academy.
A while later, they're being taught magic. SMG4 whispers to SMG3 that he didn't think he was a wizard, and SMG3 shows a note to him saying "You're gay" as the teacher continues talking. He teaches them a way by telling them to go crazy with it. Mario puts a Woody doll on the table and makes it come to life. It then begins to fight him while SMG3 laughs at him. SMG4 turns a rock into Peach and SMG3 turns a fish into Wario. Wario begins fighting Bowser. SMG4 and SMG3 are both angry and begin fighting each other. All the while, the Old Man has his back turned admist the chaos. The chaos reaches its peak when Steve turns a chair into Colonel Sanders, which shocks both SMG4 and SMG3. The teacher gives 10 points to "Gryffindor" (he possibly meant Mushroomdors) as time passes.
At the night, SMG4 begins to plan his escape, with Mario, but Mario finds a mushroom and turns it into spaghetti, but it's not the kind he likes and it goes. SMG4 tells him off and says that they need to go. Mario tells him he's hungry and he doesn't want to leave. SMG4 then takes his mustache off with magic, much to the red plumber's horror, and continues his escape. He notices SMG3 and tells Mario to shut up as he was screaming.
SMG3 is complaining to the rock wizard, about why he let SMG4 here, whom is SMG3's arch-nemesis. The rock replies that he just felt like it, and SMG3 groans. SMG4, who's noticed from afar, realizes that he has to duel with SMG3 once again. SMG4 turns around to find Mario is arguing with Hagrid, about spaghetti. SMG4 decides not to bother and angrily runs off to deal with SMG3 while they argue. SMG3 demands that he be gone, and punches the rock's hat off when he refuses. SMG4 appears behind SMG3, and tells him that he wants to be best friends with SMG3 and not fight him anymore. SMG3 disagrees and they fight about it. Dumbledore reveals he was listening in the whole time and interrupts, saying they should hold a competition the next day and the team with the most points wins their side of the arguement. They agree to it, and the next morning, they get ready.
The first goal they have is to transform their objects into a baby. SMG3 succeeds, and SMG4 turns his object into a blue Baby Mario. Their next target is chicken, which SMG3 manages to do, but SMG4 fails, creating a Colonel Sanders holding a KFC bucket. Their next target is a Pokemon, and SMG3 once again succeeds while SMG4 fails. They change players to Bowser and Mario, whom are assigned Peach. Bowser changes his object to Zero Suit Samus, while Mario manages to make Peach. They are both given an old man next, which Mario succeeds in creating (he creates Hagrid) but Bowser creates Dumbledore, whom is ejected from the round for having failed.
Dumbledore scolds them for not having a single one correct (erroneously stating this as some were transformed correctly) and looks at the points for noting if they won or not. Steve's team wins, while SMG4's comes in second.
SMG4 then laughs it off to SMG3, stating they can still be friends, while SMG3 retorts in grunts of anger, and launches himself into the sky, creating an energy ball that inverts his colors. SMG4 goes up to face him, and the two fight using their powers. Bowser and Mario, along with the others, watch from below, while SMG4 asks for help from Mario. Mario goes up there wondering how to help, and tells SMG4 he can't just fly over there. Steve offers a ride, which Mario gladly accepts, and leaves a dummy for SMG3 to hit when SMG4 vanishes. Mario laughs at him, while SMG4 charges an attack. Mario interrupts his attack to tell him to say the right thing, while SMG4 laughs it off and launches a small beam at SMG3, blowing up the sky, his powers, and the castle as well.
While Dumbledore mourns, SMG4 suggests to Mario that they back away. Dumbledore mourns for a bit, before Harry Potter himself appears, going crazy on the screen, before it ends.
Colonel Sanders (debut, cameo)
Baby Mario (cameo)
Bill Cosby (debut, cameo)
Baby Mario (cameo)
Samus Aran (cameo)
Princess Peach (cameo)
Dr. Ivo Robonik (cameo)
Harry Potter (cameo)
Carl The Minion (cameo)
Chum Chum (cameo)
Kyle Bloodworth-Thomason (cameo)
Scrivener Elf (cameo)
Eric Needles (cameo)
Trevor Troublemeyer (cameo)
Vana Glama (cameo)
Kitty Ko (cameo)
Tommy Cadle (cameo)
Melba Manners (cameo)
Dave The Minion (cameo)
Stuart The Minion (cameo)
Maggie Pesky (cameo)
Rayna Cartflight (cameo)
Phineas Flynn (cameo)
Isabella Garcia-Shapiro (cameo)
Ferb Fletcher (cameo)
Perry The Platypus (cameo)
Kevin The Minion (cameo)
Bob The Minion (cameo)
Purple Minion (cameo)
Fly Girl (cameo)