In a school world filled with boring rules and strict teachers, two best friends, George and Harold, are always on the lookout for new ways to pull pranks and have fun. Armed with their overflowing imagination, the boys decide to create their own comic featuring their original superhero: a brave captain who, curiously, is an elementary school teacher in a tight superhero suit and underpants. Everything seems to be going well until, in an unexpected turn of events, they manage to hypnotize their strict principal, Mr. Krupp, making him believe he is their paper hero.
Now, Krupp transforms into the imposing Captain Underpants, capable of turning any ordinary school situation into an exciting adventure. However, the fun doesn't last forever. With the threat of a malevolent villain seeking to take control of the school and turn it into a dull place, George and Harold must team up with their new hero to save the day. But can these boys maintain the illusion that their terrifying principal is truly a superhero while battling the forces of evil? Amid laughter, mischief, and plenty of action, this adventure is packed with messages about friendship, creativity, and the importance of not taking life too seriously. Get ready for an epic battle full of underpants and humor!