Plot
Best friends Greg Heffley and Rowley Jefferson are about to enter middle school. Greg gets advice from his older brother Rodrick on how to "survive", putting emphasis on avoiding the Cheese Touch, which supposedly makes one incredibly unpopular. Figuring that Rowley's childish tendencies will cause them to be bullied, Greg tries to urge Rowley to start acting their age, almost telling him about the cheese, but deciding against it, not wanting to scare him too much. Before long, the first day of school arrives, and Greg tries to help Rowley adjust, though both end up shunned by the majority of the students, mostly due to Rowley's somewhat childish antics, which include using the word "play" over "hang out". Nevertheless, they manage to avoid scraping the bottom of the school hierarchy.
On Halloween night, Greg and Rowley are forced to take the former's younger brother Manny with them. While at first annoyed, Greg realizes that Manny's adorable pirate costume allows them to acquire a large amount of candy. Eventually, Manny and Rowley become tired, but Greg insists that they continue on and take a shortcut through Snake Road, despite his mother Susan forbidding it. They encounter a trio of teenage boys who begin to mock and chase them with water balloons down the road. The younger boys manage to evade them by tricking them into driving their truck into a ditch and making it home right on time, only to be soaked by Greg's father Frank, who mistook them for teenagers. Manny then outs "Snake Road" to Susan, who grounds Greg from playing video games for a week.
Later on, while playing the "Rumble Trike", Greg accidentally breaks Rowley's arm. Susan discovers this but chooses not to punish Greg any further. Instead, she encourages him do the right thing and be a good friend to Rowley. Greg instead tries to take advantage of Rowley's broken arm, only to get shunned further by the other students, who dote on Rowley and demonize Greg for breaking it in the first place. Greg attempts to take a different approach and become a cartoonist for the school paper; Rowley takes an interest in a scrapped idea of his, in which the punchline of every line is "Zoo-Wee Mama!", but Greg insists on a new one he drew, urging Rowley to make his original comic instead of working together. Greg's entry gets him accepted as the new cartoonist, but the librarian butchers his comic, making his classmates mock him. After Greg resigns from his position, Rowley's comic, which features the stolen phrase, gets accepted, causing the boys to argue and break their friendship.
Rowley befriends another boy named Chirag Gupta and starts seeing him more often. In an attempt to get back at Rowley, Greg decides to hang out with Fregley, an incredibly strange and unpopular boy. Greg has a sleepover at his house but is immediately put off by his odd eccentricities. The next day, Greg and Rowley confront each other and are urged to fight by the other kids, only for the trio of teenagers to return to get revenge on the boys. The teenagers force Rowley to eat a piece of the cheese and are about to force Greg to do the same, but are stopped by Mr. Underwood, the school's gym coach.
The other students return to see what has transpired. To protect Rowley, Greg claims that he was the one who ate the cheese, causing everyone else to run from him in terror. Greg and Rowley resume their friendship as the former quickly realizes that having the Cheese Touch is a blessing as it forces everyone to give him and Rowley space, as well as a personal lunch table to themselves.
