Hearts of Nineteen

Several stories go on throughout the show, and the main story is the one focusing on the development of Gook-hwa and Yoon-hoo's relationship.

At the beginning, Gook-hwa and Yoon-hoo hate each other - Yoon-hoo despises her love for money and for behaving like a country bumpkin, while Gook-hwa detests Yoon-hoo's hot-tempered, icy exterior. He gives her the nickname "farm girl" because he finds her behavior crass. However, when Gook-hwa gets a job as Yoon-hoo's secretary, partly because of her ability to speak fluent Mandarin, Yoon-hoo gradually falls in love with her, as she is able to make him laugh and feel "alive" through her naivete and innocence.

Shin-hyung (Korean: 신형), Yoon-hoo's childhood friend whom Yoon-hoo's parents want him to marry, notices the change in Yoon-hoo's attitude toward Gook-hwa, and is uncomfortable when Yoon-hoo appears to be getting closer to Gook-hwa, despite their upcoming wedding date. Her insecurity also stems from Yoon-hoo's apparent lack of commitment to their marriage.

Yoon-hoo tells Gook-hwa how he feels about her. She initially thinks he is drunk and rejects his feelings. Yoon-hoo tells his parents and Shin-hyung that he does not want to go ahead with the wedding. His father sends him to the company's Singapore office along with Shin-hyung, who also works in the same company, as a way to make Yoon-hoo forget Gook-hwa and get him to work on his relationship with Shin-hyung.

Gook-hwa learns that Yoon-hoo is going to Singapore, and realizes that she does have feelings for Yoon-hoo. Yoon-hoo confronts Gook-hwa while he is drunk, and demands to know whether she wants him to stay. She denies any feelings for Yoon-hoo. When Yoon-hoo is at the airport waiting to board his flight, Gook-hwa constantly thinks if she should chase after him and tell him the truth. She finally makes up her mind and runs to the airport, proving her true feelings. Yoon-hoo calls her but she does not answer the phone. She eventually fails to make it to the airport before his flight, as she thinks she is crazy for running the airport.

She decides to call Yoon-hoo, only to find out that he decided not to go to Singapore, and has chosen to leave his family, even giving up his credit cards and car. In episode 89, Yoon-hoo yells at Gook-hwa, saying that “I left my house to show my true feelings about you. Can't you be more honest and give me some courage? Now, you are the only one left for me!”

Despite the objections from the world, Yoon-hoo keeps on dating with Gook-hwa. However, Shin-hyung is plotting revenge on Gook-hwa, in order to get Yoon-hoo back. Under pressure from Yoon-hoo's father, Yoon-hoo is rejected by many corporations. Gook-hwa learns that Yoon-hoo is having a hard time and decides to leave him.

Meanwhile, Shin-hyung realizes that Gook-hwa really loves Yoon-hoo through the sacrifices that Gukhwa has made for Yoon-hoo's sake.

Yoon-hoo takes Gook-hwa, who worked as a Chinese translator for him, on a business trip to Jeju Island where an important exhibition is taking place. Yoon-hoo's father, Chairman Park finds Gook-hwa and Yoon-hoo there, and soon, Yoon-hoo has returned to UT as a planning manager in the marketing department, with Gook-hwa as his secretary. Yoon-hoo also decides to help Gook-hwa become more sophisticated and sends her to an academy to help her prepare for her college entrance examination.

However, Soo-jeong (Korean: 수정), Yoon-hoo's ex-girlfriend, returns to Korea as a divorcee with her son from her previous marriage. Soo-jeong asks Yoon-hoo's mother what is she going to do if her son is Yoon-hoo's child. Yoon-hoo is shocked, and Gook-hwa realizes Soo-jeong's identity. Later on, when Soo-jeong's lie is exposed, and Yoon-hoo proposes to Gook-hwa.

Gook-hwa accepts Yoon-hoo's proposal, but persuades Yoon-hoo to return home, feeling that they have behaved rashly. Yoon-hoo agrees to her request, but Yoon-hoo's mother still opposes the marriage. On the other hand, Chairman Park decides to trust Yoon-hoo's decision, while Yoon-ji and Gwang Man support his decision as well, as Gook-hwa has gained the acceptance of Chairman Park, Yoon-ji and Gwang-man with her modesty and kind-heartedness.

A year later, Gook-hwa is pregnant, and has passed the college entrance examination. The show concludes with a scene of Yoon-hoo and Gook-hwa on a cruise ship on the Han River, celebrating her passing of the college entrance examination.

At first, Woo-kyung and Yoon-jeong meet at the funeral of Gook-hwa's fiancé. This does not start any relationship. Later, Yoon-jeong (being a bad driver) hits Woo-kyung's car and claims that Woo-kyung was at fault. Woo-kyung continues to try to avoid her, but Yoon-jeong chases him. Even though Woo-kyung tells her he is not interested, but she still chases him. Eventually Yoon-jeong says that she won't chase him anymore and she will stop wasting her time. Woo-kyung then starts to miss her presence all around, so he pursues her. In episode 95, Woo-kyung begs Yoon-jeong not to date Jin Soo and she came back to him. This eventually starts their relationship. When Yoon-jeong's mother finds out, she refuses saying that Woo-kyung has a poor background and family. However, Chairman Park, who is Yoon-jeong's father allows the marriage, claiming that Woo-kyung is too much for her. As the story goes, Yoon-jeong's mother doesn't let Yoon-jeong go out after she was greatly embarrassed in the public place by her and Woo-kyung. Woo-kyung goes to Yoon-jeong's house, firmly saying that he doesn't want Yoon-jeong to go to anymore dating.

Yoon-jeong then asks her older sister Yoon-ji what she did so that she could get their mother to let the older sister to marry. The Older sister then told Yoon-jeong that she faked her own pregnancy. Yoon-jeong then fakes her own pregnancy to her mother and her mother believes it. When she fakes it, her mother says that Woo-kyung and Yoon-jeong must be married quickly since sex before marriage is very bad in Korea. Woo-kyung and Yoon-jeong set a date and when her mother tells Woo-kyung that, he gets extremely angry. So does her mother. Yoon-jeong begs Woo-kyung and her mother for her dishonesty.

When Woo-kyung and Yoon-jeong get married, they go on a honeymoon/business trip because exhibition and honeymoon happened to be at the same time. Later in the story, you find out that Yoon-jeong actually got pregnant from Woo-kyung after their honeymoon. A recurring joke at this time is Yoon-jeong asking for something from Woo-kyung, he is going out to get it, and then she is telling him that she wants something else instead. A little later in the story, you also find out that Yoon-jeong is actually going to have twins. In the final episode, you see the twins born after the time lapse.

Later in the part, when Mr. Hong, the grandfather collapses, Woo-kyung decided to inherit his grandfather's tailor shop. Also, inheriting his grandfather's tailor shop was what he truly wanted to do. Woo-kyung's mother opposes his plan, reminding the fact from 10 years ago. However, Woo-kyung pursues his plan, with his new business ideas. A year later, Woo-kyung's tailor shop became famous nationwide, earned his fame as a great tailor. Woo-kyung earned a lot of money, however, maintains his original personality. Yoon-jeong became a mother of a boy and girl twin, still maintaining her bright characteristics.