The 2006 “Step Up” was one of the better examples of the socially-and-stylistically-mismatched dance couples that followed in the wake of “Save the Last Dance,” because it had lots of energy and a personable cast headed by Channing Tatum and Jenna Dewan. It didn’t have much of a story—just street boy and pampered girl combine their different moves in a routine while falling for one another—but even that was more of one than Toni Ann Johnson and Karen Barna have come up with for this grubby sequel. Here a lower-class Baltimore orphan named Andie (Briana Evigan), who spends much of her time with an urban street dancing group, is given a choice by her guardian: shape up or get sent to—gasp!—Texas! She opts for the former, which includes enrolling in classes at the Maryland Arts Academy, where the rigorous schedule will shatter her ties to her homeboy crew, which will not only consider her a sellout but probably expel her from the group for failure to attend their practices.

But things turn out even worse when Andie finds herself falling for handsome heartthrob Chase (Robert Hoffman), the son of the Academy’s founders, but a guy whose loose style offends his ballet-star brother (Will Kemp), the school’s principal. Chase persuades Andie that they should start their own crew featuring the school’s misfits to compete in the upcoming street competition. Of course, that leads to trouble with the jealous head of her old neighborhood gang. It also doesn’t help that the locals try to bar the schoolies from the contest, which just by chance happens to coincide with the Academy’s posh fund-raising bash.

By-the-numbers doesn’t begin to describe this wispy bit of formula plotting, which really goes into overdrive with the caricatures fashioned for Andie-and-Chase’s new crew, which include not only an Oriental girl with an impenetrable accent and a long-haired dude with bad teeth, but—I kid you not—a latter-day clone of Screech from “Saved by the Bell,” a tall, lanky, bushy-haired geek called Moose (Adam G. Sevani) who latches onto Andie and proves to be no mean hoofer himself. Predictable situations and banal dialogue fill the brief running-time, but everything that’s preceded pales beside the risibly noble speech that Andie gives at the close after her crew has been shut out of the contest, a “Let’s all be friends” oration so hokey that it would take a preternaturally controlled viewer not to laugh out loud at it.

Still, “Step Up 2 The Streets” might have been somewhat redeemed by energetic direction, engaging performers and great dance sequences. Unfortunately, neophyte helmer Jon M. Chu lets things drag along at a flaccid pace, and the combo of Evigan and Hoffman offer little of the charm and charisma of their predecessors. (Tatum turns up briefly near the beginning as a now-famous dancer who helps Andie out with her guardian, but even he lacks the old pizzazz.) As for Sevani, he might be a very nice fellow, but only devotees of Dustin Diamond could find him amusing; and Kemp is embarrassing as the martinet who—of course—folds in the face of The Talent He Didn’t Understand. The other kids can’t do anything with their cartoonish parts.

And the dances are, quite frankly, disappointing, choreographed (by Jamal Sims, Nadine “Hi Hat” Ruffin and Dave Scott) without much flair and shot by Chu and cinematographer Max Malkin (and edited by Andrew Marcus and Nicholas Erasmus) with the sort of excessive cuts and perspectives that ruin the sense of a whole routine. The big surprise of the evening is that the final set by the schoolies is staged outside in a storm, raising the question of whether the picture should be subtitled “Stinking in the Rain.”

So “Step Up 2” is a decided step down even from the mediocre original.