Nicola Yoon is a self-described “romantic goober.” She loves (and writes) young-adult romances, and she really, really loves her husband, David. The two—she’s a reformed electrical engineer from Jamaica, and he’s a Korean-American English major—met in grad school. Despite their differences, they fell in love, got married, and eventually had a daughter. Yoon’s anxious love for her child gave her the idea for her first novel, Everything, Everything, which tells the story of Maddy, a girl who is allergic to everything, and the lengths her mother will go to to protect her from the world.

But her new novel, The Sun Is Also a Star, is inspired by her relationship with her husband. It’s a romance between Natasha, a practical math geek about to be deported to Jamaica, and Daniel, the son of Korean immigrants who’s meant to be a doctor but secretly dreams of writing poetry. The details of the plot are wholly fictitious, but much of the dynamic between the pair is based on that of Yoon and her husband, especially their wide-ranging conversations. “My husband and I are very, very geeky,” she says, “and we talk about God and the meaning of life and all that stuff all the time. We stay up nights talking about that stuff.”

The conversations Natasha and Daniel have as they travel back and forth across New York City cover fate, time-travel paradoxes, and the nature of love. “I just love this idea of falling in love with someone’s brain and their ideas,” Yoon says. Of course there’s plenty of kissing too, and underlying both the intellectual and physical connections between the two is a sense of profound joy: a reminder that, no matter the complications, falling in love is exciting.

However, describing The Sun Is Also a Star as only Daniel and Natasha’s story does the novel a disservice. In telling the story of how the two fall in love, Yoon expands into the histories of those who alter their paths: from the lonely security woman who makes Natasha late to Daniel’s unrepentant jerk of a brother. Yoon’s expansive approach was inspired by the Big History Project, a movement promoting an interdisciplinary approach to history. “Subjects aren’t taught in isolation, and people don’t grow up that way,” she points out. For any two people to meet and fall in love requires a staggering number of occurrences and choices falling into place in just the right way.

Making this structure work, especially with such a diverse cast of characters, meant avoiding reductive formulas. Yoon gives even the most tangential characters (like an evangelical subway conductor) depth and dignity. These people might fulfill certain stereotypes, like the demanding Korean parents. But that’s never all they are; those parents’ expectations are based in a potent (and recognizable) mix of fear and love and leavened by their unique quirks.

Natasha and Daniel, on the other hand, are aggressively unstereotypical: a Jamaican girl planning to become a data scientist and a Korean boy with his head in the clouds aren’t exactly stock characters. But that doesn’t make them any less realistic. “That’s my real life,” Yoon says. “There are so many kids and people who are like this, and those stories should get told too.”

She’s especially passionate about exploring the perspectives of immigrants. Her family moved from Jamaica when she was 11, and that transition defined much of her outlook. “I think that the sort of typical immigrant story is that you feel trapped between worlds,” she says, “and I definitely felt that then and I feel it now.”

Nevertheless, she sees immigration as a profoundly positive choice, and the current political backlash upsets her deeply. “Immigrants come here and it’s such an act of hope, such an act of bravery,” she says. “People come here and they really want to work hard. Possibly they’re escaping something terrible, possibly they’re just coming for the American dream, but really they’re coming for a better future.”

YoonYoon’s desire for more types of stories extends well past her own experience or her own fiction: she’s also an active member of We Need Diverse Books, the buzzy organizationencouraging greater diversity in children’s literature. Despite not being much of “a joiner,” Yoon is passionate about the group’s mission—it’s deeply personal for her as the mother of a half-Korean, half-Jamaican little girl.

Though the young women in Yoon’s novels are limited by their circumstances (Maddy by her disease and Natasha by her impending deportation), Yoon clearly wants to offer her own daughter every possibility. She was thrilled to take her on a recent set visit for the movie version of Everything, Everything and be able to show her that it’s possible to follow your dreams and make a living.

Yoon’s own journey has been far from straightforward. “I always say that math led me astray,” she jokes. She discovered a talent for the subject in high school, which led her to study engineering at Cornell. Then, during her senior year, she took a creative writing elective in which she wrote terrible poetry about unrequited love. Though her poems weren’t much good, her teacher was encouraging, and Yoon found that she loved doing the work. It wasn’t until recently that she realized writing had always been a goal: she found a childhood diary entry about how she wanted to be a writer when she grew up.

These sorts of circuitous journeys are a theme in Yoon’s novels. Characters usually manage to get where they need to be, but it takes longer than they hoped and the destination isn’t always what they expected.

Ultimately, though, Yoon always brings her stories back to love. “This is going to be the cheesiest thing,” she says, “but I really believe in love, and I think it’s the best thing on Earth. I think we cannot live without it. I think it’s the thing that makes the world go round, and that’s what I write about.”

Alex Heimbach is a writer and editor in California.