"Diary of a Wimpy Kid" is the first in a series, and it features Gregory Heffley, the wimpy kid of the title, trying to survive the ups and downs of middle school. It explores relationships, popularity and the many hazards of growing up.
Written in journal format, with the addition of many illustrations, the book tells the story of Greg's first year in middle school. Greg is short and unathletic, and he suffers from bullying. He spends his time plotting how to make life more bearable and become more popular, particularly with the girls in his year. He does, however, have some solace in the form of his best friend, Rowley, who is loyal, trustworthy and even more unpopular than Greg.
However, Greg's contentment with his relationship with Rowley is shortlived. Rowley begins to become more popular because of his art, and Greg's scheming and plotting lead him to manipulate their friendship to his own advantage, endangering both that relationship and the fragile benefits he has gained.
Later, after Rowley is humiliated by some teenagers, Greg protects him in front of their peers, renewing their friendship. When Rowley is given the yearbook title Greg covets, Greg accepts this, albeit with a few words of warning to his friend not to let the accolade go to his head.