Kate Sullivan is a widowed single mother of three daughters who works two jobs while studying to be a nurse. She is assigned to clean carpets on a yacht owned by spoiled, arrogant playboy Leonardo ‘Leo’ Montenegro. Leo makes rude remarks towards Kate and fires her without pay when she refuses to bring him food. When Kate calls out his behavior, Leo pushes her off the boat along with her cleaning equipment.
Meanwhile, in Mexico, Leo’s sisters Magdalena and Sofia are tending to their ailing father. Furious when Leo is announced as his successor to run the family-owned company, Magdalena decides to visit him. That night, Leo slips off the yacht and falls into the ocean unnoticed. He wakes up on a beach with amnesia and no recollection of his identity. He wanders through town and is eventually brought to the hospital. Magdalena finds him and leaves him there unclaimed after learning he has amnesia. She returns home and falsely reports that Leo has died. Sofia suspects Magdalena is lying.
Kate and her friend Theresa see a news report on Leo’s situation. To compensate Kate for Leo’s earlier misdeeds, they scheme to take advantage of his amnesia by tricking him into believing he’s married to Kate. They go to the hospital and convince Leo of the ruse when Kate correctly identifies a tattoo on his rear, a detail she noticed on the yacht. Kate takes him home and introduces him to her girls, making up details about their alleged life together. Kate sets Leo up with an exhausting construction job working for Theresa’s husband Bobby.
Leo eventually develops a bond with the girls. Kate begins to feel guilty and considers telling Leo the truth, but changes her mind after seeing how much the girls enjoy having Leo around. Instead, they spend the evening celebrating a new revelation from Kate: it’s their anniversary. The next day, Leo discovers condoms. He assumes the worst, but after confronting Kate, Theresa takes the blame, stating she was having an affair. Leo and Kate decide to renew their vows.
Meanwhile, Leo’s family is having a memorial service for him when a picture depicting a chicken fight involving Leo is presented. Mr. Montenegro realizes the lie he’s been told and heads off to find Leo. When he gets to Kate’s house, Leo’s memory returns when he sees him. Hurt and angry, he leaves to return to his yacht. The girls tearfully run after him and plead for him to stay, but are unsuccessful.
Kate decides to go after Leo, and she and the girls rush to the pizza place to borrow Bobby’s boat to chase after the yacht. Meanwhile, Leo has become aware of how selfish and pretentious his life was before meeting Kate and the girls. He realizes he wants to be with them and has the captain turn the boat around. Mr. Montenegro attempts to stop him, but Sofia interrupts the dispute and reveals how Magdalena deceived everyone by faking Leo’s death in order to take over the company. Three horn blasts are heard, and Leo rushes out onto the deck to find Kate and the girls nearby. Kate calls out “Arturo! Arturo!” and Leo responds by yelling “Catalina! Catalina!”, a reference to a story Leo told Kate. After realizing his father has resumed course, Leo jumps into the water. Kate does the same as the two swim to each other and share a kiss. Leo dismisses threats from his father, who in the process decides to name Sofia as his new successor.
Leo returns to a life with Kate and the girls. Leo’s former employee, Colin, arrives to offer his service as a nanny. After telling him they can’t afford him, he mentions that Sofia sent him to remind Leo that he still legally owns the yacht, worth $60 million. Kate and Leo marry aboard the yacht, and friends and family toast the newlyweds during the end credits. Leo’s boat is bought for $60 million by his father who says it’s not for his benefits but for the benefit of his new granddaughters that he needs to make sure they are taken care of.