Which Korean drama is this?

The youthful Li Yongcheng (Song Seung Heon) wants to meet his friends at the airport, only to find that he forgot to bring money, just in time for the kind and beautiful Yin Xianshu (Jin Guili) to stop a car at the roadside to go to the airport. Photographer Yong Cheng, introduced by a friend, first entered the wedding company where Hyun-sook worked, and they met again and became working partners, often going out to take photos together.

At first, they hated each other. Yong Cheng doesn't like virtuous people who are serious and stubborn in everything, and sometimes even compromise for work. And virtuous also don't like A Cheng's idle and frivolous attitude. At work, they need smiling faces to greet sweet and happy couples every day, but behind the work, they often have a big fight, but unconsciously find that they can't live without each other, and their feelings soar magically.

Hyun-sook learned that she had hematologic cancer, so she had to be hospitalized and take anticancer drugs. The doctor told her that the bacteria would break out in about six months, and the specific result depends on the treatment result. Hyun-sook hid it. Everyone went to the hospital. After three days of anti-cancer treatment, Hyun-sook came home only to find a card full of love words sent to her by yongcheng. Hyun-sook was moved to tears. After returning to work in the company, she avoided Yong Cheng everywhere for fear of bringing misfortune to Yong Cheng. Yong Cheng was surprised by her behavior and couldn't help proposing to Hyun-sook, asking her to reply within three days. Hyun-sook learned from the doctor that the treatment effect was not good, and finally found a donor with the same bone marrow and temporarily changed her mind. Hyun-sook knew that her illness might be incurable, so she bitterly rejected Yong Cheng. Yong Cheng could not understand Hyun-sook's refusal. She thought Hyun-sook had cheated her feelings and was in a very bad mood. She decided to resign and leave.

Just as Yong Cheng packed her bags and was about to leave, she suddenly got a call from Hyun-sook, who fainted and was taken to the hospital. Yong Cheng rushed to the hospital and finally learned that Hyun-sook had blood cancer. The doctor told Yong Cheng that Hyun-sook had six months to live. Yong Cheng is extremely sad and cherishes her love for Hyun-sook even more. In order to take care of Hyun-sook, Yong Cheng returned to the company and promised Hyun-sook not to mention marriage again, so as to make Hyun-sook happy as much as possible.

After Yong Cheng specially held a happy and unforgettable birthday party for Hyun-sook on the top floor of his home, he couldn't help but propose to Hyun-sook again, but Hyun-sook refused. Yongcheng knew that Hyun-sook could not agree to marry herself. When he knew that the company was going to shoot the wedding ceremony and attend the press conference, he hoped that he and Hyun-sook could take this opportunity to achieve their wishes, so Yong Cheng persuaded the company to let him and Hyun-sook be models.

In the melodious wedding March, the beloved Yong Cheng and Hyun-sook slowly entered the wedding hall. Hyun-sook knew it was just a "fake wedding", but she was still very moved. When exchanging gifts, Yong Cheng solemnly put on the wedding ring she bought for Hyun-sook and told her that it was not a fake wedding, but a real one. After the wedding, Yong Cheng returned to her hometown with Hyun-sook. On the honeymoon island, Hyun-sook asked her to take a photo with her. Looking at the more and more pale virtuous, Yong Cheng put away his last smile with great pain.

Two years later, Yong Cheng became a famous photographer, and his work-Hyun-sook's last smile was made into a huge advertisement, which was hung in major subways and stations.