For “Cha Cha Real Smooth,” writer, director and star Cooper Raiff conjures up an idealized version of “the perfect big brother,” his character’s best possible self. Andrew is romantic, smart, witty, at home in his own skin and damned mature for his age — 22.

I mean, come on. Nobody is this sweet.

Raiff’s follow-up to “Sh**house” also overstays its welcome, drifts onward for too long after its climax. A fella’s got to learn when to drop the mike.

But there’s something special about a “feel good” movie that earns those warm fuzzies.

It’s a post-grad dramedy built on two premises — “Memories aren’t going anywhere.” And growing up is hard, and can hurt.

Andrew is an aimless Tulane grad who lives with his mother (Leslie Mann), adoring little brother (Evan Assante) and Mom’s new beau, Greg (Brad Garrett), almost the only guy in the movie Andrew openly despises.

He had a dream, of going to Barcelona with his Fulbright Scholar girlfriend, taking a job with a non-profit. But she went without him and he’s stuck minding the store at Meat Stick, a food court monstrosity that could only exist in New Jersey.

That changes the night he’s charged with taking brother David to a bat mitzvah. Something in Andrew’s genes, personality or upbringing drives him to “rescue” this party. A “swarm of Jewish mothers” see him coaching the DJ, cajoling the boys, then the girls and the mothers onto the dance floor, a life-of-the-party leading the party into the light.

A new profession is thrust upon him — “party starter.”

That’s not what “Cha Cha Real Smooth” is about, even though it takes its title from the “Cha Cha Slide,” even though there are birthday parties and bar and bat mitzvahs enough to keep Andrew busy in this frustrating, drifting summer after college. The film’s about what Andrew does in that guise.

He takes an interest in autistic teen Lola (Vanessa Burghardt), and even convinces her social-outcast mom (Dakota Johnson) that he can talk the on-the-spectrum Lola onto the dance in an instant. Everybody is charmed by Andrew, nobody more than Domino, that quiet, beautiful sad-eyed mother.

Over the course of that summer, he adds this relationship to all the others in his life. We see Andrew drink too much, have a fling with a high school classmate (Odeya Rush), hear him coaching his kid brother through a “first kiss,” and learn everybody’s secrets, and secret hurt.

What’s most impressive about “Cha Cha Raal Smooth” isn’t Raiff’s riffing, his character’s offhanded charm and his semi-“smooth” cha cha moves. It’s the deft way he lets the viewer figure things out.

His mom has a back-story, and Mann is wondrously touching in just a few scenes. Domino also has a story, and Johnson’s quiet, kittenish shtick takes on a sensitivity that she’s rarely played on screen.

Andrew’s relationship with one mother connects him to the other, with or without the “feelings” we know will get in the way.

He makes mistakes, and can even be flippant and cruel. But he never gives us a moment to question his values. Hating “bullies” is a given.

Any gripes I have with this Apple TV+ gem (June 17) are wiped down and wiped off in a third act is upbeat and as emotionally satisfying as any dramedy-emphasis-on-comedy this year.

Whatever he gets wrong — “Memories” do fade with age and are taken away from you, that extended ending is a bust and who names their daughter “Domino?” — “Cha Cha Real Smooth” delivers its core message with a deft touch.

Growing up is hard. And we should all be so lucky as to have a brother, friend or lover as compassionate and interested in helping us through it as Mr. Smooth — Andrew.

Rating: R, profanity, some sexual content, alcohol abuse

Cast: Cooper Raiff, Dakota Johnson, Vanessa Burghardt, Evan Assante, Odeya Rush, Brad Garrett and Leslie Mann

Credits: Scripted and directed by Cooper Raiff. An Apple TV+ release (June 17)

Running time: 1:49