Late in “Dragon Ball Super: Broly,” the 20th Japanese anime feature in a 35-year-old franchise that also has spawned scads of TV series, trading cards, video games, mangas, and limited-edition collectibles, a supporting character complains, “I don’t understand a single thing you’ve said the whole time.”

If you’re among the heretofore uninitiated drawn to this new Dragon Ball extravaganza, which has been dubbed into English and booked into 1,440 North American theaters, you may often find yourself experiencing similar frustration as you struggle to make sense of a patchwork plot that seems derived from various strands of the ongoing mythos, and is filled with apparently major characters whose backstories are only fuzzily defined.

On the other hand, the impressive opening-day box office — more than $7 million on Weds., Jan. 16 — for “Dragon Ball Super: Broly” indicate that, if this is indeed strictly a members-only attraction, well, anticipation must have been strong among the initiated to compel that kind of turnout on day one. Your mileage, of course, may vary.

Scripted by series creator Akira Toriyama and direced by Tatsuya Nagamine (a veteran of the “Dragon Ball Super” TV show), this latest movie begins as the evil Frieza — introduced here as an undisciplined adolescent who takes over the family business of intergalactic tyranny — destroys the planet Vegeta because its inhabitants, known as Saiyans, might pose a future threat. Broly, a Saiyan infant with super-warrior potential, gets away before the big bang, and spends his formative years with his father on a desolate planet called Vampa. During this period, two other young Saiyan refugees — Goku, hero of the “Dragon Ball” franchise, and Vegeta, a prince from the destroyed planet — survive and thrive on Earth, where they spend most of their time training to become champions by kicking each other’s butts with frat-boy exuberance.

Goku and Broly wind up facing off in Antarctica, in a numbingly repetitious smackdown (involving fierce punches, vicious kicks, fiery power blasts and cacophonous grunts) that takes up nearly a third of the movie. During the early stages of this battle royale, the retro look of the conspicuously under-animated visuals — which have been deliberately stylized to mimic the property’s magna roots — has an undeniable nostalgic appeal. But that’s not nearly enough to keep things interesting.

It comes as a relief when the overmatched Goku joins Vegeta in a “fusion dance” (no, really) that combines the two of them into a single entity named Gogeta, so that all the sound and fury actually can be brought to a quietus.

Not surprisingly, no one of any real importance dies during the course of “Dragon Ball Super: Broly,” thereby guaranteeing the franchise can continue apace. Indeed, the final scenes are so obviously open-ended, and fraught with promises of things to come, that the filmmakers might as well have concluded with a title card: “Stay tuned for our next exciting episode.”