Cha Jinwook, a rich playboy set to inherit his dad's company, has a chance encounter with Lee Yoomi, who has more modest ambitions to become a nutritionist.

After sharing a night with Jinwook, Yoomi departs, never to see him again. Three years later, she achieves her goal of becoming a nutritionist.

Yoomi struggles to meet the unreasonable demands of her boss. When she goes to apologize to him for a harsh e-mail, she runs into someone unexpected.

When Yoomi brings a meal to Jinwook's office, she encounters him with Joo Hyeri. Hyeri is jealous that Yoomi is cooking for Jinwook.

On her day off, Yoomi takes her half-brother, Donggoo, to Jinwook's house to cook a meal. Once there, Donggoo accidentally breaks an expensive jewelry box.

Jealous of Yoomi and Jeong Hyeontae's growing friendship, Jinwook makes Yoomi work overtime to prevent the two from spending more time together.

Yoomi agrees to pay for the jewelry box and medical fees by having dinner with Jinwook 10 times. They schedule dates for after work and on days off.

After work, Yoomi goes to Jinwook's place for a home cooked meal. Just as they're about to sit down to eat, Jinwook's father, Cha Daebok, drops by.

During a business trip, Yoomi and Jinwook stay at one of the company's resorts. Meanwhile in Seoul, the jealous Hyeri pays a visit to Hyeontae.

When Daebok sees Jinwook playing with Donggoo, he thinks that Yoomi and Jinwook had a child. Jinwook also begins to wonder whether Donggoo is his boy.

Hyeri harasses Yoomi for stealing Jinwook from her. Meanwhile, Daebok visits Yoomi's home to find out if Donggoo is his grandchild.

After deciding to quit her job, Yoomi leaves Seoul and moves to Daejeon to work at a university dining hall. One day, Hyeontae comes to visit her.

Yoomi blames her mom for her misfortune and goes to the beach where she first met Jinwook. He learns of Yoomi's whereabouts and they reunite.