Diary of an Awesome Friendly Kid: Rowley Jefferson's Journal

Diary of an Awesome Friendly Kid: Rowley Jefferson's Journal is a spin-off of the Diary of a Wimpy Kid series by Jeff Kinney. Unlike the main-series books, which are written from the perspective of Greg Heffley, Diary of an Awesome Friendly Kid is written from the perspective of Greg's best friend, Rowley Jefferson, acting as Greg's biographer. The book was released on April 9, 2019. A sequel, titled Rowley Jefferson's Awesome Friendly Adventure was released on August 4, 2020, delayed from an initial release date of April 7, 2020. A third book in the spin-off series, titled Rowley Jefferson's Awesome Friendly Spooky Stories was released on March 16, 2021.

Plot
Rowley starts his diary by explaining that he started writing in one because his best friend, Greg Heffley, owns one as well. In the second entry, Rowley shows his diary to Greg, who accuses Rowley of copying him. Greg then comes up with the idea that Rowley's journal should be Greg's biography. Rowley complies, and changes the title of his diary from Diary of an Awesome Friendly Kid to Diary of Greg Heffley by Greg Heffley's Best Friend Rowley Jefferson.

Rowley starts the biography with a chapter titled "Early Life," and skips ahead to when he first met Greg in fourth grade. He writes that he likes Greg for "doing hilarious things," then changes topics to his first sleepover with Greg, where he pees his pants after getting scared by a noise outside. Other entries focus on when Rowley saves Greg from attending a birthday party after falling in a hornet’s nest, Greg's "accomplishments" (a blank list for Rowley to fill in later when Greg accomplishes something), Rowley tripping over a rock and Greg telling him he disturbed an "ancient burial ground," Rowley believing that his deceased grandfather has come back as a ghost to haunt his cabin, Greg playing a "wacky prank" by pretending to be a burglar, and Rowley mishearing Greg's request to "pull him back up on his feet" after he loses his balance, instead grabbing Greg by the feet and causing him to fall in a puddle, angering Greg.

In Rowley's entry about "the time when Greg created a special award just for me," Greg gives Rowley a "good boy award" for cleaning Greg's garage. Greg gives Rowley more awards for doing his chores, and after Rowley says that they aren't special anymore because he has so many, Greg makes a "point system" instead, with Rowley's reward for getting 50 points being a basket of dirty laundry.

Rowley then writes about "the time I found out Greg is a lousy study partner." While studying for a math test with Rowley at the library, Greg tries to make a secret code and cheat on the test. Opposed to the idea of cheating, Rowley suggests that they study separately, and Greg slips a mean note between the dividers. This leads to Greg and Rowley making entire pages of rude drawings with "that's you" notes, and they get kicked out of the library after Rowley chases Greg.

In the next entry, "the time I made the worst mistake of my life," Greg cheats by copying Rowley's entire test, even writing Rowley's name. They both get in trouble, and while Greg is given 3 days of detention and forced to take the test again, Rowley is given a warning. He gets upset after he is warned not to cheat. Rowley writes about "the time Greg totally had my back" next, hoping that Greg won't get mad for making him look bad. The class gets a new teacher, who is not bothered by the students acting crazy and not doing any work. Everyone, including Rowley, gets a "C" grade. Greg complains that Rowley was the only one who did classwork, causing the teacher to increase Rowley's grade to a "B." When it was raining, Greg loses his temper when he was playing Twisted Wizard and breaks the controller. Rowley then brings up an anecdote in which he and Greg draw their own superheroes. In the penultimate diary entry, Rowley has a sleepover at Greg's house, where they sneak out to bounce on a trampoline. Greg's parents get mad and his mother divides his and Rowley's room in half. Greg draws an "invisible forcefield" that "zaps" Rowley if he tries to pass through it. Greg prevents Rowley from using the bathroom, and he pees out the window in the morning. The sleepover ends with Greg flushing one of Rowley's action figures down the toilet.

Rowley shows Greg his biography, and Greg is angry that it focuses on both him and Rowley instead of just him. Rowley suggests that it could be their biography, but Greg threatens to change all the parts with Rowley. Rowley changes the diary's focus back to himself. The book ends with Rowley's parents telling him he should find new friends, and Rowley responding that he can't because Greg takes up a lot of his time. Rowley believes that since Greg's mother says that friends get on each other's nerves, he and Greg must be "best friends" since they get on each other's nerves the most.

Development
A shorter Wimpy Kid story from Rowley's point of view was written to celebrate World Book Day 2019. Kinney later developed it into a full-length book, becoming Rowley Jefferson's Journal, because he enjoyed writing it.

In an interview on the official Wimpy Kid YouTube channel, Kinney described that he noticed "the audience [...] always rooting for Rowley" in the Diary of a Wimpy Kid movies. This inspired him to write a novel from Rowley's point of view. On the subject of the book's illustrations, Kinney said that he liked how his art style is still recognizable even though Rowley "draws like a five year-old." He stated that he enjoyed writing the book and that it is his favorite book in the series, because he likes how Rowley is unable to keep the book's focus on Greg. When asked if the series would change to focus entirely on Rowley, Kinney confirmed that he will continue to write main-series books, but that he would also "really like to write more Rowley books," because "it's a lot of fun, and I think it's really fresh, and [Rowley] can write in lots of different styles about lots of different genres. So I'd really like to get to there, where Rowley is authoring lots of books." The following year, a follow-up to Rowley Jefferson's Journal, titled Rowley Jefferson's Awesome Friendly Adventure, was published. Rowley Jefferson's Awesome Friendly Spooky Stories, another sequel, was released in March 2021.