A young broccoli boy is celebrating his birthday while his friends are wishing him a happy birthday. The broccoli boy then proceeds to make a wish and blow out the candle, but before he can blow out the candle on the cake, a wind suddenly picks up that blows away the cake and the presents, sucking them up into a huge tube, while the broccoli boy yells out, "This is not what I wished for!" Inside the Larry-Cave, LarryBoy is showing Bob his hideout, while Bob tells him that it's a cool hideout, to which LarryBoy then answers, "It's a living". However, at that moment, the alarm then rings out as LarryBoy then approaches the Larry Computer, who tells him that Mayor Archibald is sounding the distress signal. When LarryBoy says, "On screen", the computer then brings up Archibald, who tells LarryBoy to get over there quick because someone is stealing birthdays. LarryBoy then tells Archibald that he's on his way before going over to his changing screen, but accidentally changes back into Larry again, before changing back in LarryBoy again, while Bob tells him to be careful, to which LarryBoy answers that he's always careful to save the day, before hopping into the Larrymobile and driving away. However, Bob realizes that he's now trapped in the Larry-Cave without any way to get out.
LarryBoy then drives to where the broccoli boy's birthday party was stolen, where the people then frantically tell LarryBoy about what happened. Archibald then tells the people that LarryBoy will figure it out, before asking LarryBoy if he will, which LarryBoy confirms, saying that no kid deserves this. When LarryBoy asks the people who stole their birthday parties, the broccoli woman answers that it was a big machine, and that Corn Mom heard it with her own ear. LarryBoy then asks Corn Mom, "Is there a kernel of truth to this story?", before Corn Mom answers that "he's stalking our birthday parties." LarryBoy then hears his Super-Suction Ear ringing, before he answers it, the caller being Junior Asparagus, telling LarryBoy that he's at Laura Carrot's birthday party. LarryBoy then asks Junior what kind of cake they're serving, but Junior tells him to never mind that because the party is under attack. LarryBoy then says, "Another one? I'm on my way!" The broccoli boy is still sad about his birthday being stolen, but LarryBoy tells him not to cry, telling him that he can play with a nuclear chronoplasmere (which looks more like a banana peel), explaining to the broccoli boy that it shifts time. LarryBoy then drives off after that, while the broccoli boy says, "My hero."
At Laura's birthday party, Junior is trying to stop the presents from getting blown away, when Laura, who is in one of the gift boxes gets blown away, while she happily proclaims that her wish has come true, which is that she is flying, not realizing the danger that she is in. After Laura and the party gets sucked up, LarryBoy then shows up asking what happened, with Junior telling him that he's too late, because the party's gone. LarryBoy then says, "At least things can't get any worse", before Junior tells him that Laura got taken away with the gifts, which LarryBoy is dismayed to hear, saying that he has to come up with a plan. Back in the Larry-Cave, Bob is still trying to find a way to get out, to no success. Bob then hops up to the Larry Computer and looks at all of the buttons, trying to find which one will get him out, before he presses a random button, but unfortunately, it turns out that this button that he just pushed has activated the hyper-recline action on the chair he is sitting on, before the chair then catapults Bob, sending him ricocheting all over the Larry-Cave. Back in town, LarryBoy and Junior are riding in the Larrymobile while following a trail of presents and cake, which had been left behind by the machine that stole the birthdays, the trail leading straight to Motato's lair. Junior pleads to LarryBoy that they have to find Laura, because she's his best friend, but LarryBoy tells him that he's going to find her, telling Junior that "There's no 'we' in 'I'm gonna find her'." Junior pleads to LarryBoy to let him help, which LarryBoy consents to, which Junior is happy to hear.
In Motato's lair, all of the stolen presents, including the one that Laura is inside, are being deposited onto a conveyor belt, while the Radish soldiers are retrieving the stolen presents. After arriving at Motato's lair, Junior asks LarryBoy how they're going to get inside, but fortunately, LarryBoy comes up with an idea on how to get into Motato's lair. The plan involves LarryBoy and Junior hiding inside gift boxes with a birthday cake in front of them while singing the "Hap-Hap-Happy Birthday" song. At first, nothing happens, but when LarryBoy blows out the candle on the cake, a wind then picks up that sucks up both the cake and the gift boxes that LarryBoy and Junior are hiding in, sucking them into Motato's lair. Back in the Larry-Cave, Bob then comes up to the changing booth that Larry uses when becoming LarryBoy so decides to use it to try to get out of the Larry-Cave. Unfortunately, when Bob gets into the changing booth, it only causes a spare LarryBoy helmet to get stuck on his head, which obscures his vision. Bob then falls onto the chair and accidentally presses the button that activates the hyper-recline, which catapults Bob once again. After LarryBoy and Junior have made it into Motato's lair, they peek out from their gift boxes, but hide again when they see two Radishes coming up to the conveyor belt. One Radish tells the other Radish that "Small, squishy presents that are probably socks or undies go in the trash pile", while the other Radish then adds that, "And the big presents and delicious cake go to Motato. I know." The gift box that LarryBoy is hiding in then falls on top of that one Radish, who then comments that "this one is heavy."
When no one is looking, this Radish then opens up the gift box, but is met with a surprise when LarryBoy uses his Super-Suction Ear to send that Radish flying until he lands in the toilet. After that Radish has been taken care of, LarryBoy tells Junior that they've got to find Laura. The two then start looking amongst all of the various stolen gifts, trying to find Laura, with Junior telling LarryBoy that "it was yellow with a white bow". LarryBoy and Junior then look to see Motato helping himself to some stolen birthday cake, with one of the Radishes wishing him a happy birthday, but this infuriates Motato, telling that Radish not to say that, because no one ever remembered his birthday growing up, which is why he plans to destroy all birthdays, not celebrate them. The other Radish then tells Motato, "Then, happy not-birthday boss", before Motato orders that Radish to get him another present, which that Radish does. LarryBoy and Junior become surprised when they see that the present that the Radish brings to Motato is a yellow one with a white bow, which is the same one that Laura is inside, before LarryBoy then uses his Super-Suction Ear to retrieve the present from Motato's clutches. Motato is surprised to see LarryBoy, berating him for stealing his stolen present, with Junior telling him, "It's not a present! It's Laura!", but Motato claims that he doesn't know a Laura, but does know a tack, which confuses LarryBoy, before Motato orders the Radish soldiers to attack.
The Radishes then surround LarryBoy and Junior, but LarryBoy picks up Junior then approaches the conveyor belt before throwing a stolen birthday cake as it flies up into the air before landing on top of the Radishes. With the Radishes subdued, LarryBoy and Junior escape with the present before opening it up, telling Laura that she can come out now, but they are surprised to find that Laura is not in the gift box. Seconds later, Laura then appears next to them, asking them what they're doing. At first, LarryBoy does not realize that Laura is right next to him and Junior, explaining to her that they were just trying to rescue her, before realizing that she had escaped Motato's clutches, before Laura then leaves after that. However, Motato's face then appears on the Larrymobile's computer, as Motato then explains that he has a special present for the whole house, which is that now that he has stolen all the birthdays, he will make sure that no one has a birthday ever again, telling LarryBoy to prepare for the De-birthday-ficator, which confuses LarryBoy. Motato then starts singing a rap song about how it's his "unhappy not-birthday" and that he's thrilled because it's his worst day, and intends to make sure that everyone's wishes don't come true, because he has a De-birthday-ficator that he plans to steal birthdays from everyone. After the song ends, LarryBoy and Junior are both shocked to hear this, before Motato then activates his De-birthday-ficator telling the two that it is now to steal birthdays from vegetable-kind, and that he's going to freeze them all.
On the street, Jimmy "double-dog dares" Jerry to lick the pole. Jerry refuses, but Jimmy assures him that "you'll only get stuck if it's frozen". Jerry then proceeds to lick the pole, just as a cold wind then blows up, and sure enough, Jerry ends up getting his tongue stuck to the pole. The other veggies then start to feel cold, as it turns out that the cold wind is from Motato's De-birthday-ficator, which is now blowing from the vent. LarryBoy then notices that it's really getting cold, while Junior says that Motato is going to freeze the whole house. Motato then says, "Once frozen, you'll never have another birthday ever again! You hear me? The De-birthday-ficator!" After Motato's image disappears from the screen, LarryBoy then says, "That's cold, man", while Junior adds, "That's one mean tater". The Larrymobile then drives off while LarryBoy tells Junior that they have to close the air-conditioner vent before the whole house freezes, before driving off to the courtyard. The Larrymobile then arrives at the vent where the cold wind is blowing from, while Archibald tells LarryBoy to help them because it's freezing, while the broccoli boy asks LarryBoy if he saved his presents, but LarryBoy tells him, "Not exactly". LarryBoy then leaps out from the Larrymobile, saying that they won't give up without a fight, asking who's with him, before he suddenly gets cold.
Back in the Larry-Cave, Bob manages to get the spare LarryBoy helmet off his head, before hopping up to the tube that Larry uses to travel down to the Larry-Cave, just as he starts to hop up the tube in an attempt to make it out. Bob is almost a few steps out, when he accidentally steps on a lobster that was somehow in the tube, which causes him to slide back down the tube before crashing next to a push-button raft, which he then pushes, which causes the raft to expand and send Bob flying again, while Bob says, "I didn't know LarryBoy had a push-button raft". After the raft folds back down to its small size again, Bob thinks that the raft is fun, before he hears LarryBoy say that "the cold is coming out of this vent. We've gotta cover it." The broccoli woman pulls out a sandwich, which LarryBoy throws at the vent, but the wind blows the sandwich back as it hits him in the face. LarryBoy then says that they need something bigger to clog the vent, before Corn Mom pulls out two sandwiches. Larry then throws the first sandwichaway before he starts shivering from the cold. After seeing the whole thing on the Larry Computer, Bob realizes that Larry is in trouble and that he needs to get out of the Larry-Cave. Fortunately, Bob comes up with an idea on how to both get out of the Larry-Cave and save everyone in town. Bob then hops back into the chair again before pressing the hyper-recline button again, which then causes the chair to catapult Bob up the tube, bringing him back inside the house again before he goes off to help LarryBoy.
The cold wind from the De-birthday-ficator still continues blowing from the vent, which causes LarryBoy, Junior, and the others to feel even more colder, while LarryBoy says that "cucumbers are made up of 192% water, and I'm freezing up!" The broccoli mom says that they need a superhero to save them, which offends LarryBoy, which the broccoli mom apologizes to. Bob then shows up with the push-button raft, telling LarryBoy that he's coming. After Bob comes down and makes a soft landing with the raft, LarryBoy asks him if he's going rafting, with Bob answering that he's saving him. Bob then hops up to the vent while carrying the raft, even when LarryBoy tells him that it's too cold and that he can't do it. After coming up to the vent, Bob then throws the raft into the vent, as the raft then expands, blocking off the cold wind and saving everyone from getting frozen to death. Back in Motato's lair, the De-birthday-ficator then short circuits and goes into reverse, which then causes all of the presents and cake that had been stolen to get ejected back out, which Motato is shocked to see. Outside, everyone is happy to see that all of the birthdays have now been saved, but LarryBoy then says, "Not everyone's birthday". Motato is still sad about not having a not-birthday, when he suddenly hears something, before seeing a birthday cake and a present set out for him, which he is happy to see, saying that it's his birthday. Underneath, LarryBoy and Junior then wink at each other, having accomplished their act of kindness to Motato.
- This is the second time a villain gets a happy ending in the LarryBoy franchise; the first was in the book Larryboy and the Amazing Brain Twister.