“Forever…,” the 1975 Judy Blume YA novel about teenagers losing their virginity, has inspired a Netflix series with changes you’re free to regard as substantial or superficial. Premiering Thursday, it’s a very sweet show, full of characters whose differing needs and ideas sometimes put them at odds, but who are for the most part very nice. The worst you can say about any of them is that they are clueless or confused in the way that people, especially young people, with their incompletely formed brains — a scientific fact someone raises helpfully — often are.

I’ve never read any of Blume’s books, though I have read reviews and synopses of “Forever…,” and visited Reddit groups where contributors recall secretly passing the novel around in high, middle or even elementary school — Blume (already a kid-lit superstar for “Are You There God? It’s Me, Margaret”) plus sex being an irresistible combination: adolescent hot stuff, mid-’70s style. I can report at least that in both the novel and the series, a character has named his penis Ralph.

The TV show, created by Mara Brock Akil (“Girlfriends”), cuts the ellipses from the book’s title. The characters are Black, a change that is both superficial and substantial. It honors the shape and intent of the novel while adding issues not on Blume’s agenda regarding Black culture and advancement. More significantly, the series has been set in the near-present day — 2018 — and moved from quiet suburban New Jersey to sophisticated, sprawling Los Angeles. The first episode is directed by Regina King (“One Night in Miami”).

Things have changed in the half-century since “Forever…” was published, even subtracting the years the series backtracks. Not that teenagers weren’t falling in love and having sex — or not falling in love but having sex — in the year that Captain & Tennille released “Love Will Keep Us Together.” But the texting and blocking, the free-for-all backwaters of the internet and the carnal shenanigans that color contemporary TV teendom do put a different complexion on growing up. Of course, young people can be having a lot of sex while not, in the strict formulation, “having sex,” if you get my meaning. Yet a show about a couple of high school kids who, whatever else, have never Gone All the Way, and take the prospect seriously, can feel like a throwback to more innocent times — and that is not a bad feeling at all.

Justin (Michael Cooper Jr.) and Keisha (Lovie Simone) are our young lovers, who meet, or meet again — they had known each other in elementary school — at a New Year’s Eve party, thrown by Keisha’s rich but not snooty friend Chloe (Ali Gallo), the series’ only regular white character. (There is fondue, the whitest of all foods.) Justin and Keisha come from different sides of the tracks , or “the 10,” in L.A. psychogeography; his family has a big modern mansion in the hills, while she lives with her mother, Shelly (Xosha Roquemore), in an apartment down around Slauson and Crenshaw.

Keisha is an A student (and track star) whose friends call her Urkel; her mother struggles to pay for the Catholic school to which she’s recently transferred. A full-ride scholarship to Howard University is in her sights, and there’s no reason to think that she won’t get it, even with a sex tape that’s gone around.

Justin, who has “a learning difference” and problems with “executive function,” struggles in school, but his mother, Dawn (Karen Pittman), a successful executive — it’s one of those jobs that requires barking into a phone while walking quickly through a room — has supplied him with tutors and wants big things from him; he’s not sure what he wants. (Mother and son alike may be putting perhaps too much faith in Justin’s ability to shoot three-pointers when it comes to college admissions.) His father, Eric (Wood Harris), who cooks for the family and runs restaurants — including, in this TV reality, the real-life Linden, a Hollywood center of Black society — and never went to college, is more easygoing. (“Life works things out when it’s supposed to,” says he.)

The kids are honest and sincere, not stuck up, not phony. Keisha seems a little more on top of things, life-wise, though she will jump to conclusions. Justin, less interested in whatever high-powered business future his mother imagines for him, dreams of a career in music, which in this context means “making beats.” Though Simone and Cooper are not actual teenagers, they are fresh-faced and radiant and youthful; they’re pretty adorable. Their parents, too, are likable, loving, hard-working people, a little bossy now and then, but genuinely concerned for their children. As in the real world, the kids handle some of their business better than their elders, and sometimes the elders prove wiser than the kids. (Not too often though — this is a series aimed at young viewers, who won’t have come for a lecture.)

Keisha and Justin bumble into and out of a bad first date, but before too long, he’s texting her, “think I woke up with a girlfriend can u confirm” and she is replying “how can I be ur girlfriend if u haven’t asked me.” (He will.) Things get better and worse and better, happier and sadder and so on, as the couple travels through eight episodes of mostly ordinary drama — jealousy and insecurity, mopiness and mooniness, desolation and elation, miscommunication and reconciliation — on the way to maturity. They’ll get into minor trouble with school and parents. The infamous sex tape — something shot by Keisha’s former boyfriend, Christian (Xavier Mills), but distributed by an offscreen character — leads to a conversation or two, but is more or less old news by the time story begins. Justin isn’t bothered.

Interestingly for a modern teen show, nobody’s getting drunk or doing drugs, apart from a couple of pot-smoking adults and flirty old friend Shannon (Zora Casebere), who comes on to Justin during the family’s annual summer decampment to Martha’s Vineyard. “I want you to be my first,” she says, “It would be awkward and we would laugh through it.” He thinks love should have something to do with it.

As a coming-of-age story, it’s more about the electrifying present than the unwritten future, however often that future comes up for discussion. Ultimately, it leads our heroes to the common enough question of what happens to their union after graduation. Not to give anything away, but anyone who’s survived their youth will understand that the title is ironic — or, with Blume’s ellipses, reattached for the title of the final episode, at least inconclusive.