Mr. Garrison is warned by the school board that he will lose his job if he can't prove that he teaches his class about the current events, so he makes them all write a report. Stan, Kyle, Cartman and Kenny are paired with the jittery and stressed out Tweek. Mr. Hat threatens the boys with violence if their report doesn't "kick ass".
Meanwhile at Tweek Bros. Coffeehouse, a representative of Harbucks attempts to get Mr. Tweak to see his coffee shop for a Cramsonite briefcase, to which Mr. Tweek declines. The representative then offers him $500,000. Mr. Tweek again declines. Angered, the representative states that he will open Harbucks right next to Tweek Bros. Despite the fact that it will likely put Mr. Tweek out of business.
After school, boys go to Tweek's house for the night to write about the "Underpants Gnomes" that are stealing Tweek's underpants. Mr. Tweek, believing that Tweek merely loses his underpants, tells the boys that they could write about the big corporate bulldozer trying to put his coffee shop out of business, but Mrs. Tweak objects.
In the night, Mr. Tweek comes in and discovers the boys haven't done a report, but gives them a report he wrote for them about big corporations. While he is talking, the boys miss the gnomes that sneak in and take Tweek's Underpants.
At the presentation, the boys give "their" presentation to the committee. While Mr. Garrison sees through the ruse, the committee believes this is the boys' original work and subsequently decide to side the town to the boys' "cause". Mr. Garrison then tells the boys to go with this to the end or else.
The town committee goes to Tweek Bros. Coffeehouse and see the huge Harbucks opening next door. The committee assures Mr. Tweak that they will fight for his coffeeshop's survival by taking the fight to the mayor's office. Mayor McDaniels says she can't just force them out so she decides to make the town vote on Prop. 10 and see what happens from there.
The boys soon end up on talk shows and advertisements as the poster boys for the anti-big business band wagon. Mr. Tweak is thrilled by the attention their getting, but Mrs. Tweak is disgusted with the idea of using kids in political ads to promote and sell political beliefs. She promptly states she'll have no more to do with the situation.
The mayor decides to host a debate in front of the competing coffeehouses and decides to host vote there the next day. The committee asks The boys to write a 5-minute speech for the debate. The boys again go to Tweek's house to write the speech, but don't know anyone who knows about corporation. To everyone's surprise the Underpants Gnomes appear, stealing Tweek's last pair of underpants. Stan asks a gnome why they steal underpants to which the gnome says,"Stealing underpants big business!" Seeing an opportunity to find someone who knows about corporations, the boys accept his offer to follow the gnome home.
In their village, the boys ask how their corporation works. The way the gnomes make money is rather pointless. Phase One: collect underpants. Phase Three: profit. When they ask what Phase Two is, it is revealed that there is no Phase Two. The boys are confused about what phase two means and ask if they know anything about businesses. They tell them for a small price - underpants.
At the vote, the boys reveal they didn't write the report, and explain the importance of big corporations. Without them we wouldn't have computers, or cars. Even Harbucks started as a small business and because of its excellent product, became a big business. This speech leaves the crowd stunned until Mrs. Tweak applauds them and joins them on stage. Mrs. Tweak tells the crowd that they kept complaining and protesting but never bothered to try Harbuck's coffee. With this, the crowd, and even Mr. Tweak, tries and loves the coffee and admit its superiority over Tweek Bros. coffee. The Harbucks representative then offers Mr. Tweak the job of running the store, to which Mr. Tweak accepts.