Despite her mother Patricia's protests, seventeen-year-old Natasha gathers her phone, headphones, and physics homework and heads for the USCIS building in Manhattan. Her little brother, Peter, gleefully packs boxes while blaring Bob Marley, and her dad, Samuel, just looks angry. They're undocumented immigrants and are being deported today. Natasha believes this is her last chance to convince anyone to let her stay in the US. At the USCIS building, the security guard, Irene, takes her time looking through Natasha's things, making her late for her appointment. She lingers over Natasha's phone case, which is the cover art for Nirvana's album Nevermind. Later, Irene listens to the album and after researching Kurt Cobain, she decides to commit suicide. It's something she's been thinking about for a while. Meanwhile, a new agent, Lester Barnes, agrees to see Natasha. She's distraught at his apathy, but finally, he gives her a business card for Attorney Jeremy Fitzgerald, an immigration lawyer in town. She secures an appointment for later that day.
Meanwhile, Daniel prepares for his admission interview for Yale. His mom, Min Soo, was very upset after Daniel's perfect but mean older brother, Charlie, was forced to withdraw from Harvard, so she's pinning her hopes on Daniel getting into Yale so he can be a doctor. Daniel doesn't care much for being a doctor; he wants to be a poet. Charlie happens to walk into the kitchen right as Min Soo tells Daniel to not be like Charlie, and Daniel decides to escape the house early and take the train into the city for a haircut before his appointment. The conductor stops the train a few stops away from Daniel's, and he tells his passengers to go find God. Daniel decides to walk the rest of the way and let fate guide him. He sees Natasha walk into a record store called Second Coming Records and decides to follow her, since it seems like a sign.
In the record store, Natasha sees her cheating ex-boyfriend, Rob, making out with a girl named Kelly. Kelly is stealing records, which astounds both Natasha and Daniel. When Rob approaches Natasha, Daniel accuses him of stealing and scares him off. Natasha has no interest in making friends and leaves the store without introducing herself to Daniel. He follows her out of the store and watches her get lost in her music at a red light. When Natasha steps off the curb, she doesn't notice a white BMW running the light. Daniel pulls her back and they fall, breaking Natasha's headphones. Daniel invites Natasha to get coffee with him, and she grudgingly introduces herself and agrees. At the coffee shop, they ascertain that Daniel is Korean American and Natasha is Jamaican, and Natasha loves science while Daniel is a poet at heart who believes fully in true love. He looks up a study that found 36 questions that can supposedly cause two people to fall in love, and he decides to make Natasha fall in love with him "scientifically."
Natasha and Daniel begin working through the questions as they walk uptown for Natasha's appointment, which she refuses to tell Daniel about. They're obviously attracted to each other, though Natasha doesn't want to admit it. At the office building, Natasha is sad when they part ways but they both reason it's for the best. At Attorney Fitzgerald's office, Natasha learns from his paralegal, Hannah Winter, that he was hit by a car that morning and won't be in until later. Natasha returns to the lobby where she finds Daniel, who postponed his interview. The two decide to go to Harlem so that Daniel can deliver a money pouch to his dad, Dae Hyun, at his store. Natasha is unsurprised when she discovers that Dae Hyun owns a black hair care store, as Koreans own most black hair care stores. Daniel initially asks Natasha to wait outside so they can avoid Dae Hyun's offensive racism, but Daniel decides to ask Natasha to come in anyway. In the store, Charlie taunts Natasha and Daniel, while Dae Hyun tries to offer Natasha, who wears her hair in an Afro, relaxer to "make her hair not so big." Daniel finally drags Natasha out of the store, mortified. Natasha laughs at the absurdity of it, but she is touched when Daniel sincerely tries to apologize for the racism in the world.
Natasha accepts Daniel's invitation to have lunch at his favorite Korean restaurant. On the train into the city, they talk about their complicated relationships with their fathers. Natasha doesn't ask any embarrassing questions about the food, though the waitress does rudely refuse to bring her a fork. She doesn't understand why Daniel tells people he's from Korea when he was born in America. After they eat, Daniel leads her next door to do norebang, or Korean karaoke. Norebang is done in small booths instead of a large room, so it's far more intimate. Daniel sings an ABBA song and is a skilled singer and performer. Natasha does a horrendous rendition of a very depressing Soundgarden song and after, she and Daniel kiss. Natasha feels emotion like she's never felt before; she was worried she was incapable of love after discovering she wasn't so upset about Rob. The kiss is intense and finally, they stop. Outside on the street, Natasha has to remind herself that the hustle and bustle of the city is real life, and she begins to shut down on the train to the Museum of Natural History. Daniel wants to know what she's afraid of, which begins a fight as they reach Central Park. Daniel is angry that Natasha won't admit that there's something between them, and he can barely comprehend it when Natasha tells him that she's an undocumented immigrant set to be deported in mere hours. They angrily part ways.
Natasha goes to the museum anyway and looks around the Hall of Meteorites. She finds the idea that two people falling in love is significant ridiculous in light of all the small things that had to go right to create the universe. Daniel writes sad poetry, and the narrator finally explains what happened between Natasha and her dad as Natasha returns to Attorney Fitzgerald's office. Samuel came to the US to be an actor but soon became disillusioned and stopped auditioning. Finally, a few months ago, he got a part in A Raisin in the Sun, his favorite play. Patricia had been unimpressed and had flat-out refused to attend opening night. After the play, Samuel drank too much and was charged with a DUI. In the process, he told the officer that he was undocumented, thus bringing about the deportation notice. Attorney Fitzgerald is confused as to why Samuel would ever do such a thing, but he believes he can reverse the notice. In her relief, Natasha decides to go back to Dae Hyun's store to try to locate Daniel and tell him the good news.
Daniel returns to his dad's shop to confront Charlie. As he and Charlie fight, Daniel understands that Charlie failed at Harvard because he was suddenly not the best anymore. After their fight, Dae Hyun tells Daniel that if he doesn't agree to go to Yale to become a doctor, he won't offer any financial help. The narrator explains that Dae Hyun just wants to give his sons a better future after his own experience of poverty in Korea, and he has very definite ideas about how that's best done. Daniel decides to return to Natasha's building in Manhattan with the hope of finding her. Unknowingly, the two cross paths at the Manhattan subway stop, and they both give money to a street violinist. When Natasha reaches the store, Charlie agrees to give her Daniel's phone number, which the narrator asserts is the only nice thing he'll ever do. When she calls Daniel, he's thrilled to hear from her, and he apologizes for trying to insert himself in her business. Natasha takes the train back to Manhattan to Attorney Fitzgerald's building, which Daniel realized is the same building where he needs to be for his interview. They discuss all the coincidences of the day, though they disagree whether they're fate or just coincidences. When Natasha tells Daniel that she might be able to stay in the country, she's so overcome with joy that she decides to call Lester Barnes to ask him to thank Irene, as Irene holding her up that morning is what set off the chain of events that brought her to Daniel and to Attorney Fitzgerald.
Daniel signs in for his appointment and leads Natasha to the roof. The door is locked, but a security guard who has clearly been smoking happens to come off the roof. Natasha scolds the man for smoking. She reminds the man so much of his late wife, and Natasha and Daniel remind him of how he and his wife used to look at each other, that the guard allows them onto the roof. Natasha and Daniel kiss and then begin working through more questions. Daniel explains that he believes God is the name for all the interconnected good parts of all people, while Natasha tells Daniel about dark matter, which keeps the universe from flying apart. Daniel insists that dark matter is love.
Daniel is late for his interview with Attorney Fitzgerald. When he enters the office, Hannah Winter is crying, but Fitzgerald ignores her and calls Daniel in. Daniel notices Natasha's file on Fitzgerald's desk, and he and Fitzgerald have a frank conversation during which Daniel admits that he has no interest in going to Yale, while Fitzgerald confides in Daniel that he's cheating on his wife with Hannah Winter. Fitzgerald admits that he wasn't able to save Natasha, and the narrator explains that instead of calling a judge, Fitzgerald spent his afternoon with Hannah. Later, he'll decide to leave his wife for her. Daniel is distraught and decides that he needs to tell Natasha himself. He finds her in the lobby, where she ignores Attorney Fitzgerald's calls and cries when Daniel tells her what happened. Daniel declares that he'll accompany her home and then to the airport.
Natasha is ashamed of how rundown her neighborhood is, and she chafes under the stares that she and Daniel attract. At the apartment, Daniel is ashamed when he realizes how poor Natasha's family truly is. The apartment is in total disarray because of the packing, and Samuel is angry that Natasha has been gone all day. Natasha finally confronts her dad and tells him that when they get to Jamaica, he has to actually try to make it as an actor and can't live in his dreams anymore. Natasha and Daniel take a cab to the airport together, and they stare into each other's eyes for four minutes as the final part of the study. They tell each other they love each other before Natasha gets on the plane.
Daniel and Natasha try to keep in touch, but soon grow apart as Natasha tries to assimilate into Jamaican culture. Daniel attends Hunter College part time, while Natasha discovers she loves physics. Natasha never knew that she saved Irene's life by making the phone call to Lester Barnes, as it gave Irene the strength to call a suicide hotline and get help. She becomes a flight attendant and ten years later, she recognizes Natasha on one of her flights. After a moment, Natasha recognizes Irene, and she realizes that Daniel is sitting mere seats away.