It only took a year for the sequel to “Diary of a Wimpy Kid” to arrive, which might explain why this new movie shares the same likable quality as the first, and sports one important advantage over other kid-movie sequels: The child actors haven’t grown a foot and a half between films.

“Diary of a Wimpy Kid: Rodrick Rules” reunites us with the main characters from Jeff Kinney’s comics. Greg (Zachary Gordon) is the wimpy kid, now entering seventh-grade and still loyal to his somewhat embarrassing best bud, Rowley (Robert Capron).

Greg’s also got a crush, in the form of a new girl who is, without question, out of his league. That doesn’t stop our hero from trying to snag a dance during a roller-skating outing or passing her a note during class, two attempts at being noticed that have equally mortifying results.

As the title suggests, Greg’s older brother Rodrick (Devon Bostick) gains even more devilish control over his little bro’s life. This time the siblings have a chance to bond when they must join forces to cover up the effects of a party from their parents (Steve Zahn, Rachael Harris).

That cover-up, and its consequences, plays out over the course of much of the second half of the movie.

One of the surprising and low-key achievements of these “Wimpy Kid” movies is that somebody seems to have actually spent time thinking about the screenplay, and crafted the story with a minimum of overblown nonsense.

These films also have agreeable actors. Harris and Zahn, as Every-Mom-and-Pop, are content to do their background roles and then let the kids (including local lad Karan Brar) take center stage. Most of Zahn’s performance consists of standing behind Rachael Harris and making funny faces as she lectures the boys, which is not a bad way to go.

This sequel, like the first film, is modest. I can’t say I’d recommend it to anybody other than 12-year-olds and the parents who are pretty much obliged to go with them, but at least the experience won’t be too painful if you fall into those categories.

And give the movie credit for accurate details: like the fact that no matter how wimpy or nerdy a guy like Greg might feel, there’s always another wretched kid, far more hapless, who isn’t even aware of how geeky he is. In this case, his name is Fregley. He doesn’t stand a chance.