Eleven years before the main story, 14-year-old Laniah Thompson and her best friend, Issac Jordan, a Black boy living with foster parents across the street in Providence, Rhode Island, steal their bully's bike. Laniah's father, Dennis Thompson, teases her about Issac before telling her to walk with courage and trust her instincts. That afternoon, Dennis struggles to breathe through a guitar melody, the beginning of an undiagnosed illness that will reshape the family.
By 25, Laniah is closing Wildly Green, the natural hair and body product shop she and her mother, Vanessa Thompson, opened three years ago, which has fallen into serious debt. Dennis died of heart failure nine years earlier, and Vanessa has grown quieter and more withdrawn. Laniah works a second job as a hotel housekeeper and has not told Issac about the shop's failure. Issac, now a famous mixed-media artist, model, and influencer living in California, surprises Laniah during a brief visit home. She notices an unfamiliar distance in his embrace. He and Melinda Martinez, a model he had been dating, have split, and tabloids question his ability to commit. Laniah confesses the shop is closing. Issac insists he has a plan to help, asking only that she trust him.
Issac posts a photo of himself and Laniah on social media with a caption implying they are a couple. Laniah wakes to thousands of follow requests, and customers line up at the shop. Their friend Lex Chen, who manages the shop's social media, initially believes the relationship is real but soon grows suspicious, confronts Laniah, and agrees to support the scheme. They establish rules: no kissing on the lips, a firm end-of-summer deadline, and total secrecy. Issac's public image benefits from appearing committed while Wildly Green gains the exposure it needs.
The plan works immediately. Issac posts a photo carousel of their shared history, sending waves of customers to the shop. They sell more in one day than they had in six months. But scrutiny follows: paparazzi photograph Laniah leaving her hotel job, and tabloid articles question whether she is with Issac for his money. Issac goes live to defend her. Meanwhile, Laniah's health quietly deteriorates. Her doctor, Dr. Rotondo, dismisses her concerns about headaches and elevated blood pressure, attributing them to stress and prescribing Prozac without investigating further.
Laniah flies to California for her first public outing as Issac's girlfriend, attending a listening party for her favorite singer, Shida Anala, who requests a custom hair-care plan from Wildly Green. On the dance floor, physical tension between Laniah and Issac becomes unmistakable. They acknowledge the chemistry but agree not to cross further lines.
Back in Providence, Laniah transforms Wildly Green into an interactive "Experience" where customers receive custom-made hair and skin products. Laniah quits her hotel job after an emotional goodbye with Bridget Murphy, a 70-year-old permanent hotel resident who has become like family. Bridget reveals her decades-long estrangement from her sister Wilma, Laniah's neighbor, which began after Bridget left Rhode Island following their grandmother's death.
Issac flies home for the grand reopening, bringing extravagant bouquets and tulips for Vanessa, echoing the flowers Dennis used to bring her. The reopening is a massive success. However, Darius, a man Laniah had briefly dated, retaliates after she refuses to serve him at the shop by posting their private texts online, including an underwear photo she once sent him, and claiming she cheated on Issac. Bernie, Issac's manager, negotiates a settlement: Darius signs a nondisclosure agreement, recants publicly, and deletes his account.
On Laniah's front lawn, Issac suggests ending the fake relationship a week early to protect her. He brings his lips barely to hers and asks what she wants. She stammers that she does not know, and he backs away. Laniah surprises Issac by flying to California for the Year of the Lotus art exhibition. The exhibition is a triumph: Issac showcases a painting of his late mother and curates work by emerging artists. In front of cameras, Laniah impulsively kisses him on the lips for the first time. He deepens the kiss. Later, Melinda privately tells Laniah that Issac was never going to be her soulmate because "it was always you" (249), and encourages Laniah to admit she loves him.
That night, Laniah and Issac sleep together. He tells her he prayed it would not feel this good because he does not know how he will let her go. They agree to spend the weekend as a real couple, then take a week apart to decide their future. At the airport, Issac confesses he has been in love with her since they were 13, when she found him crying on bleachers, bought him Starbursts, and let him have all the pink ones. Laniah tells him she is in love with him too.
During the week apart, Laniah's health crisis reaches a devastating head. Lex takes her medical records to his cardiologist boyfriend, Shane, who consults a nephrologist, Dr. Baldwin. They determine that her lab results, flagged repeatedly over years, are consistent with stage-three chronic kidney disease, a condition in which the kidneys have lost significant function. Dr. Rotondo had never disclosed the diagnosis. Shattered, Laniah texts Issac that she cannot be with him, claiming the risk to their friendship is too great. Privately, she believes she is sparing him a future of caretaking and grief, the same suffering she watched her mother endure with Dennis. Issac calls and texts repeatedly, but Laniah holds firm, asking him to announce their breakup.
Laniah begins treatment with Dr. Baldwin, who outlines lifestyle changes and reassures her that many patients live long lives. Vanessa forces a raw conversation, asking whether Laniah believes she does not deserve love because she is sick. Vanessa tells her she would endure Dennis's illness and death all over again for "an ounce of our happiness" (329). Laniah begins recalling forgotten moments: her parents dancing in a thunderstorm, her mother learning guitar at Dennis's bedside, his final laugh. She realizes she has fixated on grief while forgetting the joy.
Vanessa tells Issac about the diagnosis. On a FaceTime call, he argues that Laniah's disease does not define their relationship, and that while she witnessed only her parents' suffering, he witnessed a love so strong "even the doctors couldn't predict how long they'd get to have it" (333). Laniah insists they remain friends, and Issac ends the call. Days later, he releases a video unveiling
A Love Like the Sun, a massive collage dedicated to Laniah. The piece contains artifacts from their entire history: childhood Polaroids, Dennis Thompson's pen, his mother's ring that he once traded for Laniah's name bracelet, and a preserved pink Starburst wrapper. In the video, Issac declares Laniah his soulmate. She watches at the shop, clutching the ring on her necklace, and recognizes that he has called her home.
Issac shows up on Laniah's porch in the rain carrying bags of low-sodium groceries. He tells her he will move back to Providence, accompany her to appointments, and give her his own kidney if he is a match. Laniah confesses she was about to book a flight to him. She tells him she wants to be with him and asks him to be brave when she cannot. They kiss, and she pulls him into the rain to dance, echoing her parents in a thunderstorm.
An epilogue, presented as items added to the collage, reveals their shared future: articles naming Wildly Green's Experience a Best Beauty Start-Up, medical results charting Laniah's kidney health with unchanged and improved readings, and photos from a wedding at the Roger Williams botanical garden, where Laniah walks toward Issac wearing something blue from Bridget. The final entry notes that another canvas has been added to the first, leaving space for the rest of their lives.