In “The Baby-Sitters Club,” the charming Netflix adaptation of Ann M. Martin’s wildly popular children’s book series, there’s a witch. Not the cauldron-stirring, spell-casting sort of witch. This isn’t that kind of kids’ story.

Instead, Esme Porter (Karin Konoval) is a “spiritual practitioner” who hosts “share-a-monies” in suburban Stoneybrook, Conn. “Witch,” she says, is a name that’s come to be used for “people, primarily women, who refuse to conform to society’s expectations of who they should be.”

This makes a pretty good mission statement for the tween entrepreneurs of “The Baby-Sitters Club,” and for the show itself. It is in one sense exactly what the title says it is: a show about seventh-graders who start a babysitting business. But it also defies expectations, and exceeds them.

It’s a richly character-based story about growing up, dealing with change, growing apart from and back together with friends. It’s sweet but not cloying, smart but not cynical, full-hearted and funny enough to please both grown readers of the original books and the young target audience of the new series — and even plenty of viewers (like me) who are neither.

The 10-episode season begins with “Kristy’s Great Idea,” in which Kristy Thomas (Sophie Grace) concocts her business idea when her mother, Elizabeth (Alicia Silverstone), is stymied finding last-minute child care.

Kristy, a steamroller of confidence, persuades her friends Mary-Anne Spier (Malia Baker) and Claudia Kishi (Momona Tamada) to start the club, which eventually adds new girls Stacey McGill (Shay Rudolph) and Dawn Schafer (Xochitl Gomez).

The series jumps out of the gate with a rich sense of the girls’ characters and the nuances of their relationships. Artistic Claudia has been distant from Kristy. Introverted Mary-Anne worries that her friends are growing more sophisticated while she still dresses “like the world’s oldest toddler.”

Essentially, the show is a procedural, in which the cases involve not crimes but kids: a trio of tiny terrors, a morbid little girl who holds a mock funeral for her doll. On top of this are longer arcs, like Elizabeth’s engagement to jovial rich guy Watson Brewer (Mark Feuerstein), whom Kristy stubbornly resists.

Showrunner Rachel Shukert (“GLOW”) and executive producer Lucia Aniello (“Broad City”) have created a “Club” that’s a throwback in its optimism but firmly rooted in 2020, from its multiracial casting to its story line about cyberbullying to its girl-positive sense of humor.

“Baby-Sitters Club” centers installments around its pint-size girl-bosses and has them trade off the narration. In one standout, Claudia uses her art to connect with her grandmother after her stroke, and unearths the story of her having been in a Japanese American internment camp. In another, sheltered Mary-Anne struggles with asserting herself. Babysitting gives her a voice, especially when she looks after a trans girl, for whom she sticks up when adults misgender her as “he.”

The characters learn to take care of themselves by taking care of others. There are adversaries, like a group of older teens who steal the girls’ business idea. But there aren’t really bad guys. Instead, everyone has a story; everyone has decency that can be reached. What makes a good babysitter has a lot in common with what makes a good TV show: seeing even the most troublesome individuals not as problems but as people with needs. “Behind every tantrum,” as Dawn sagely says, “There’s something else.”

It’s heartwarming but not heavy. The present moment that adults have created can be a bummer, but this piece of smartly reworked nostalgia is optimistic that future adults might do better and know better. As Esme puts it, “When children tell you something, believe them.”

“The Baby-Sitters Club” takes the witch’s lesson to heart, and the result is pretty magical.