Telling a good love story on the big screen is a challenge of originality in 2017. The trite and cliche rom-com narrative is over burdened with expectation and is running on empty, and the year’s best rom-coms have relied heavily on shattering the formula (even “The Big Sick,” the most typical of romantic comedy of the year, is also one that challenges stereotypes and confronts nuanced culture clashes). It’s no surprise then that the documentary form has answered the call and offered up one of the most surprising and thoughtful romantic comedies of the year in “Dina.”

“Dina” ostensibly follows a classic narrative: a woman is engaged to be married and is wrestling with the upheaval that comes with shacking up, planning a wedding, and beginning a life together — all while in her late 40s. Only Dina and her partner Scott are on the autism spectrum and the sensitive and humane movie that captures their romance is both utterly familiar and anything but typical, a study of the catholic nature of love and partnership and the unique and recognizable challenges that lie therein.

“Dina” tells the story of the titular and indomitable leading lady as she asks her fiance to move in with her and they work to settle into a normal life. He works as a Walmart greeter, they take trips to Ocean City, hang out with friends, plan their wedding, and struggle to find comfort and rhythm in their sex life. Like so much else in “Dina,” this normal life is a study in paradox: Dina and Scott’s lives are familiar and so too are many of the challenges they face, but their circumstances — the cost of their daily joys — are profoundly different from the normal Hollywood has served us for a century. Which makes “Dina” sound like a film designed to teach, but it’s not that either; didactic movies are made only for the lessons they embody, and reducing “Dina” to that is to miss the point completely.

“I wonder what a honeymoon is like when people deeply have passion?” Dina muses while she and Scott take a walk during their Poconos vacation. It’s the sort of question that cuts to the core of the film: what experiences are we missing? What realities are we blinded to in the fog of our private perceptions?  

What makes “Dina” so humanistic is part and parcel with what hinders it. Directors Dan Sickles and Antonio Santini’s cinéma vérité style, which goes so far as to make the film look and feel scripted, drops us into the mundanity of Dina and Scott’s life. And while it does wonders to add texture to the careful and nuanced portrait of Dina, it takes far too long for the film to find its footing and settle into an engaging tenor. Still, it’s hard to fault Sickles and Santini (whose previous film “Mala Mala” focused a similarly humanistic lens on trans-identifying people in Puerto Rico) for showing such respect to Dina and the humble life she is living.

The joy of “Dina,” of course, is Dina, who carries herself throughout the world without shame for who she is or what she’s been through. She’s quick to tell strangers on buses that she is on the spectrum, that her first husband passed away, that she was a victim of a harrowing, violent assault. And while many might view that as the sort of unwelcome and unwarranted openness of those on the spectrum, it comes across as genuinely trusting, as though Dina sees a goodness in the world and is unafraid to confront it.

Throughout, “Dina” is hilarious, and never at the expense of Dina or Scott or any of their friends. More often “Dina” is funny because Dina and her friends are genuinely funny people and because they are so unabashed. One particular delight is Dina’s racy bachelorette party, which sees Dina and her bridesmaids befriend a male stripper and have what honestly seems like some of the most fun captured on film in a documentary this year. Which makes “Dina” entirely worth it — its pace may drag and its hook may come 15 minutes too late, but the joys it mines are undeniable. [B+]