A kid named Greg is starting middle school with his friend Rowley. Greg and Rowley experience a variety of different events including wrestling, wizard of OZ play, getting ambushed by teenagers on Halloween, and safety patrol. Greg and Rowley drift apart as friends but later on there friendship rebuilds.

To Greg Heffley,middle school is the dumbest idea ever invented. It's a place rigged with hundreds of social land mines such as morons, wedgies, swirlies, bullies, lunchtime banishment
to the cafeteria floor and the cheese touch. To survive the never-ending ordeal and attain the recognition and status he feels he so richly deserves Greg devises an endless series of can't-miss schemes all of which, of course, go awry. And he's getting it all down on paper via a diary - "it's NOT a diary it's a journal!" Greg insists, preferring the less-sissyfied designation filled with his opinions, thoughts, tales of family trials and tribulations, and (would-be) schoolyard triumphs. "One day when I'm famous," writes Greg.