'Love at First Sight': Haley Lu Richardson, Ben Harding lead Netflix's most popular movie

The most popular movie on Netflix right now, Love at First Sight, based on the book "The Statistical Probability of Love at First Sight" by Jennifer E. Smith, has its stars Haley Lu Richardson and Ben Harding proving the rom-com era has returned.

Narrated by Jameela Jamil, Love At First Sight uses numbers as a way to tell this love story.

We're first introduced the two people at the centre of this movie. Hadley (Richardson) is the kind of person who is late 21 per cent of the time, which is usually the state of her phone battery as well. Oliver (Hardy) is the exact opposite, on time 94 per cent of the time.

They're both travelling through New York's John F. Kennedy International Airport on the worst travel day of the year with 193,000 passengers in the airport, with an average of 23-minute delays at check-in and 117-minute wait time at security.

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Hadley is going to London to see her dad, who's about to marry a woman she's never met, after Hadley's parents got divorced. Oliver is originally from the U.K., travelling home for a memorial for his mother who has cancer and has made the decision to forego any treatment.

The pair may seem like an unlikely match initially, but after an airport meet-cute and sitting next to each other on the flight from New York to London (thanks to a little help from Jamil's narrator character), they can't stop thinking about each other when they land at their destination.

In true rom-com fashion, Oliver puts his phone number is Hadley's phone, but she drops it, which cracks the screen and shuts down the phone, losing the phone number.

But a connection between their two families in the U.K. could bring these two back together.

'You're always worried about making sure the readers are happy'

For the book's author, she admitted that she was "worried" about how her beloved story would be handled for a movie.

"I think as the author, you're always worried about making sure the readers are happy, because this is a book that came out in 2012 so readers have lived with it and loved it for a very long time," Smith told Yahoo Canada. "But the moment I started talking to all the people involved, I knew the story was in very good hands."

"Everyone from the screenwriter, Katie Lovejoy, who just loved the book and put so much of it into the script. The first time Vanessa [Caswill] and I spoke, she had a copy of the book that was all highlighted and marked up, and was actually interested in adding even more from the book into the script at that stage. ... I never worried."

For director Vanessa Caswill, what she loves so much about the book is that it's so full of "heart," and presents a classic love story in a different structure.

"You get all this time with them on a plane, which is certainly ... rare on screen," she said.

"You'd freak out normally that ... no one's moving from this plane for ages, but they're just getting closer and closer and closer together. And then they're split and there's something so wonderful about that, and wanting them to get together again, wanting them to find each other."

Working with the 'claustrophobic' setting of an airplane for a rom-com

A significant obstacle Caswill had to overcome was how to translate a story that largely takes place in a confined space — first the airport, and then an even more confined space an airplane — in a way that will entice an audience to continue to watch this relationship evolve.

"I remember talking to the producers about, gosh it's just too much to ask an audience to sit through all these scenes on a plane, without people being able to move or have a new kind of background or anything," Caswill said.

"We obviously felt really confident that what was happening between the characters, and also the kind of intimacy of the plane getting darker and everyone around them sort of disappearing off, out of the light, made it feel like it was just something that was sort of pulsating and alive, and definitely worth sitting with for that amount of time."

Notably, "Call Her Daddy" podcaster Alex Cooper's fiancé, Matt Kaplan, is credited as a producer of the movie.

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The film wasn't shot entirely chronologically, with the airport and plane portions of the story shot earlier on. But the final scene of the movie was in fact the final scene that was filmed.

"It was quite interesting just actually being in those different spaces and feeling really claustrophobic, and then feeling like, 'Ah, we've got some space,'" Caswill said. "It has an energy and a rhythm to it that kind of sits with the structure of the story."

The director also worked with Hardy and Richardson in rehearsals on their use of physical space.

"They just had a really wonderful, playful energy between each other," Caswill said. "We worked a lot in [rehearsals] on space, on how they inhabited space, how they were when they were together. How they were when they were apart, how they looked at each other across space."

For Smith, what's particularly unique about her book "The Statistical Probability of Love at First Sight" is that while it's a story targeted to young adults, it crosses between different generations of readers. That's also something the author believes stays true for the movie.

"The characters are aged up a bit in the film and even in the book, because it's about the two of them but it's also about their families, it has always appealed to to a younger audience, but it has also always appealed to an older audience," Smith said.

"I think it's a really interesting time, whether the character's 17 or 22. She's at a crossroads in her life and it's a coming of age story in a day. In this one day she's opening herself up to the idea of love, to the idea of a relationship with her dad, to travel by herself to this new place and these new people. I've always been really attracted to the idea of how much one day can hold, in that way. I think that's true, whatever age you are."