The prologue to “Cobra Kai,” on YouTube Red, reiterates the climax of its esteemed predecessor, “The Karate Kid,” from 1984. At the All-Valley Karate Tournament, limping Daniel LaRusso delivers a championship-winning crane kick to the head of his vicious opponent, Johnny Lawrence. The knavish foe sprawls prone on the mat. The camera pulls in on the yellow serpent embroidered on the back of his black uniform. And, in the present day, Johnny wakes up face down in his cruddy apartment, with a pulverizing hangover. The thrashing incited thirty-odd years of uneasy dreams. The series is here to assess their toll.

“I’m not here to rehash the past,” Johnny (William Zabka) later says—or was it Daniel (Ralph Macchio)? I admit that the bold falsity of the statement stupefied me such that I garbled my notes. Here, rehashing the past is essential to the characters’ motives and the audience’s desires. “Cobra Kai” is not merely a sequel to “The Karate Kid” but a gleeful explication thereof. It is so mired in the nineteen-eighties that even its glaring flaws—its trite gestures, cheap jokes, and junior-varsity production values—have the quality of aesthetic choices designed to transport the ideal viewer to the entertainments of his Reagan-era youth.

The blow of the crane kick stunted Johnny’s emotional growth; his casual racism, reflexive sexism, and chronic old-fogeyism reflect the mental habits of a man too pained by contemporary life to adjust to it. Yet his crassness can seem nearly attractive, given the tang of Zabka’s dry delivery, and because the actor has always indicated that Johnny was both a bully and a victim—an innocent pit bull trained in malice by a rabid master, his sensei.

On “Cobra Kai,” Johnny first dusts off his karate moves to intervene when a pack of high-school bullies start roughing up his neighbor Miguel (Xolo Maridueña). Yielding to the puppyish pleas of this fatherless young man, Johnny begins to teach Miguel self-defense, indoctrinating him in the Way of the Fist: strike first, strike hard, no mercy. He opens a dojo, Cobra Kai, in a Reseda strip mall, between a kebab shop and a vape place; the enterprise struggles until the freaks and geeks among Miguel’s schoolmates enroll. Johnny’s grouchy-old-man routine is especially effective when his new protégés introduce him to the concept of cyberbullying. Horrified, he says, “Back in my day if you wanted to tease someone, you did it to their face. There was honor, respect.”

Meanwhile, Daniel has grown prosperous as the owner of LaRusso Auto Group. Because the series posits a world in which Greater Los Angeles hails the youth-league martial-arts champions of yesteryear as enduring folk heroes, its commercials depict Daniel using knife-hand strikes to chop the prices of Hondas and Audis, and his catchphrase brays, “We kick the competition!” Has success spoiled Daniel LaRusso? He’s no villain, but the series has made an intriguing choice in stripping away his underdog charm. Daniel seems notably self-important when glad-handing at the Encino Hills Country Club and irritatingly self-satisfied when whipping up banana pancakes for his two kids. His smugness is not entirely sufferable, and it is galling that he should be so disturbed by the resurrection of his rival’s old dojo that he sets the goal of destroying it.

The tidy coincidences of the plot clink together such that Daniel becomes the karate mentor to Johnny’s estranged son, who develops a crush on Daniel’s daughter, who is stealthily dating Miguel. All of this teen cheese goes down smoothly enough, given its context, which is that of a show that may have decided to endow Daniel with a car dealership just so that his student can wax every hood on the lot. There is room for something like a character study within the borders of the caricature offered by “Cobra Kai.” Its attention to Johnny’s maladjustment is a hard kernel of realism pinging off its nostalgic bits, fan-club philosophizing, and its broad analyses of the mean girls and teen bullies of the twenty-first century. In short, it’s a teen show for Gen X-ers.