The story begins with the kinky school troublemakers, George Beard and Harold Hutchins, two boys who are known by almost every one of their teachers as disruptive and rude. George and Harold love to play pranks on the helpless kids and teachers at Jerome Horwitz Elementary School. They are also known schoolwide for the comic book series that they create and sell on the playground, known as "The Adventures of Captain Underpants", their favorite super hero. They have many enemies (all of them being the faculty teachers). But the one who despises them most is the school principal, Mr. Krupp. Mr. Krupp hates them, their pranks, and especially the Captain Underpants comics. He vows to get them one day ("one day very very soon" he claims).