Cartman is shown talking about how all recent music videos contain women singing about their vaginas. Butters joins them at the lunch table with a black eye. Stan asks why he doesn't have a lunch, easily seeing through Butters' excuses. The other boys nonchalantly respond, resulting in Stan criticizing them. Red congratulates him on this. After asking Butters if a bully took his lunch money, he recommends telling a teacher or the principal about the bully. Butters refuses; Kyle recommends talking to his grandmother about the problem and Butters decides to do so.
Butters' mother, father, and grandmother are shown talking. Shortly afterwards, Butters appears, asking if he can speak to his grandmother privately. After his parents leave the room, she began to abuse him by slapping him, calling him a faggot, and saying that he is her "bitch". Butters parents enter the room shortly after this, resulting in her resuming her sweet false demeanor.
A anti-bullying spokesperson is shown in Mr. Mackey's office, telling him about how widespread a problem bullying is, Mr. Mackey isn't nonchalantly responds, causing the spokesperson to become angry and "bully" Mr. Mackey. This reduces Mr. Mackey to tears. As a result, Mr. Mackey announces a mandatory assembly on bullying.
Meanwhile, Red tells Butters that his grandmother is looking for him, much to his chagrin. He attempts to hide in the restroom, however, she was already in there. She mistakenly believes he is the one who brought in the anti-bullying spokesperson, calling him a "narc" and attempting to make him put a urinal puck in his mouth. However, Richard Adler attempts to open the door only to find out it was locked. She quickly makes up a cover story, saying that Butters took her to the incorrect bathroom. Shortly before she follows Richard to the correct bathroom, she threatens Butters with death if he "narcs on her again".
The aforementioned anti-bullying spokesperson is seen at the assembly, explaining bullying and attempting to get someone to direct an anti-bullying music video. After the spokesperson taunts the students, Stan volunteers to make the video.
During the video, Butters says he no longer wants to participate, as it will "only make things worse for him". This upsets Stan, who asks him if he wants to be bullied the rest of his life, much to Kyle's chagrin. Stan stops Kyle from leaving, attempting to see what's wrong. After Stan claims that he's making the video to stop bullying, Kyle tells him to stop acting, that the video is less about bullying and more about him. Kyle leaves, but not before warning Stan that he should be careful, otherwise he'll end up "naked and jacking it in San Diego", confusing Stan.
Butters, his parents, and his grandmother are shown at the dinner table. His grandmother is shown sticking a fork into his thigh under the table, causing Butters to writhe in pain. This confuses his father, who asks what's wrong. Butters claims he is simply gassy. Stan, Kenny, and Cartman later enter the room, saying a Hollywood executive bought their music video.
Stan enters the school, everyone cheers for him, greatly pleasing him. Stan later enters the restroom, where the anti-bullying spokesperson is shown waiting for him. The spokesperson claims that the video was Bucky Bailey's Bully Buckers' property, as it was his idea. After the spokesperson taunts him, Stan begins crying.
Meanwhile, Butters is in his room, contemplating whether he should defend himself against his grandmother. He decides that he must, and puts on his costume, going to his grandmother's room. To his surprise, she is also wearing a costume. Butters is frightened and attempts to run, however, she catches him and assaults him.
The anti-bullying spokesperson is seen entering the restroom, where the movie executive who bought the anti-bullying video is waiting for him. He tells him that the video is, in fact, the student bodies' property, handing him a cease and desist letter and threatening to sue him if he attempts to claim any authorship of the video again.
Kyle is shown entering the bathroom, where Stan is waiting for him. After a brief argument, Kyle claims that if he wants the video to be seen by everyone, he should put it out on the internet for free. Stan refuses to respond to this, telling Kyle to leave because he's "trying to go to the bathroom". Kyle leaves, telling him that he will not help him when he is "naked and jacking it in San Diego".
Stan and Butters are seen on The Dr. Oz Show, talking with Dr. Oz about bullying. After Butters refuses to say anything, Dr. Oz becomes aggressive, asking Butters if he actually cares about the victims of bullying. This upsets Butters, who snaps and beats him up. As a result of this, the Hollywood executive yells at Stan. Afterwards, the executive enters his bathroom, where Jesus is shown waiting for him. Jesus warns him about Hell, then taunts him, asking if he's going to cry.
Meanwhile, Butters enters his grandmother's room, telling her he realizes now that there are just people out there like her, and when she's in the hospital dying, he'll visit her and show her that she didn't defeat him, that he moved on and she is still miserable and alone.
Afterwards, Stan is shown entering the school, where the student body "boos" and throws paper balls at him, much to his chagrin. Clyde, Cartman, and Craig explain that the U.S.'s populace is upset, thinking that the video must be fake due to Butters' breakdown on The Dr. Oz Show. Red and Timmy later join in, booing him, with Red saying he made the student body look like "uncaring idiots". Mr. Mackey then informs him that Dr. Oz is suing Stan and the school; Mr. Mackey wants to know what Stan is going to do about it. Stan then realizes the only thing he can do.
Stan is shown traveling to San Diego. After arriving, he goes to a street corner, undresses himself, and begins masturbating, much to the amusement of San Diego's populace. His fate remains unknown afterwards.
AV Club gave "Butterballs" a "B" rating saying: "Some episodes of South Park find the satirical eye of Trey Parker and Matt Stone aimed at an abstract concept. Other times, it’s pretty clear that they are going after one specific event or individual. “Butterballs” managed to do both at once, with slightly mixed results. I tend to prefer when the two aim big with their episodes, as those tend to have a greater shelf life and wider applicability above and beyond initial airing. Whereas the cultural firestorm around the movie Bully and the “Kony 2012” movement provided some of the show’s biggest laughs, what will linger the longest sat in the periphery."
IGN gave "Butterballs" a "7.5" rating saying: "Indeed, there were some pretty awesome bits tonight. Unfortunately, some of that was marred by an obscure reference to a video that almost nobody had seen as well as a few too many scenes that screamed, "Hey look, we're actually bullying! Get it?" However, I will say that overall it was nice to see a South Park episode that stuck to its guns thematically. It was, for the most part, an episode fully dedicated to lampooning one single subject, which is a plus in my book."